Re: Computing hour lines for horizontal sundials

[Roger Bailey]

Hello Bryan,
Cut to the chase. Use the trig equations directly. Solve with a simple
scientific calculator. No worries about logs or radians.

My background is similar to most of the others who provided good advice on
old fashion methods.  Over the last 50 years I have junked log tables,
sight reduction tables, my log log slide rules and most of my old
programmable calculators.

Welcome to the arcane abstruse world of sundial design.

Roger Bailey, Peng
Walking Shadow Designs
 Sidney by the Sea, BC

On Mon, Aug 8, 2022 at 10:50 PM Bryan Mumford  wrote:

> I’m working from Albert Waugh’s book “Sun dials, Their Theory and
> Construction”. On page 45 he presents a method for computing hour lines. I
> lack significant math skills, but I know how to work Excel. I don’t
> understand how he is calculating these values.
>
> He says, for example, that “log tan t” of 7°30’ is 9.11943.
>
> In my simple-minded way I asked Excel to show me log(tan(7)) and got a
> very different value.
> I tried converting 7°30’ to radians and that didn’t get any closer.
>
> How can I calculate "log tan t" or "log sin latitude” with Excel to get
> the values he shows?
>
> I anticipate further problems with the last two columns, but you have to
> start somewhere….
>
> - Bryan
>
>
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Telling time with a rope?

[Roger Bailey]

At the NASS conference in 2005 in Chicago, Stephen Luecking gave a Rope
Geometry Workshop, "Laying Out a Sundial on the Landscape Using Ancient
Rope Geometry".This was based on his paper "Rope Geometry: History and
Methods" These described other methods for telling time with rope,different
from Marchants . People used what they had at hand.

Roger Bailey

On Thu, Mar 3, 2022 at 11:45 AM Jack Aubert  wrote:

> I tired searching for “pommeau de ciel” and “pommeau des cieux”, which not
> surprisingly I did not recognize in either English or French.  Pommel is
> Pommeau in French.  I mostly got hits for shower heads and gear shift
> knobs… but did find a reference to the original French on Google Books:
>
>
>
>
> https://books.google.com/books?id=BVtcMAAJ=PA108=PA108=pommeau+de+ciel=bl=4NKJk6haHD=ACfU3U0xr9oORL7S6zs-nKRg-NnTizDKfQ=en=X=2ahUKEwiD_trVyqr2AhVlkeAKHacJDbwQ6AF6BAghEAM#v=onepage=pommeau%20de%20ciel=false
>
>
>
> But reading the text, it does appear that “pommel of the sky” could only
> refer to Polaris, as Steve surmises.  That being said, I have to suspect
> that Guy Marchant came up with this method, that would be beyond the
> interest the vast majority of shepherds, on his own.  A shepherd, who is
> probably illiterate, is supposed to identify a star and remember to adjust
> its time position throughout the year?  Also, why would he care what time
> it is at night?  Maybe they taught that in advanced shepherd class.
>
>
>
> Jack
>
>
>
>
>
>
>
> *From:* sundial  *On Behalf Of *Steve
> Lelievre
> *Sent:* Thursday, March 3, 2022 2:17 PM
> *To:* sundial@uni-koeln.de
> *Subject:* Re: Telling time with a rope?
>
>
>
> Hi,
>
>
>
>  I think the pommel of the sky refers to the celestial north pole, i.e.
> where we see the Pole Star or Polaris.
>
>
>
> Then, on the summer solstice hold a plumb line in front of you such that
> it obscures the Pole Star, and find another circumpolar that is also hidden
> by the plumbline.  In the rest of the year, the angular displacement of
> this second star tells you how far from midnight you are, provided you make
> an adjustment of 1 hour per half month.
>
>
>
> For the method to work, you need to have established midnight on the
> summer solstice. This is done by fixing two plumb lines one behind the
> other, so that they are aligned to the solstice's midday sun, i.e. they
> show you the meridian. I think the text is saying that on the day of the
> summer solstice, as the shepherd faces north looking through the plumb
> lines, if Cancer is seen slightly to the east and Capricorn slightly to the
> west, then it is midnight (presumably that's only in the British Isles).
>
>
>
> I got this  from a rather quick scan of the text, so I may have missed
> something. There's also discussion of the learning the rising positions of
> the signs of the zodiac but I don't quite follow how it relates to the rest.
>
>
>
> Steve
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> On 2022-03-03 10:11 a.m., Dan-George Uza wrote:
>
> Hello,
>
>
>
> In the "Kalendar and Compost of Shepherds" by Guy Marchant, an illustrated
> work translated from French into English in the early 1500s, there is a
> chapter with the following title: "Shepherds practise their quadrant at
> night as you see by the figure hereafter". Could someone more versed in old
> English please explain how this technique actually worked? I attach the
> relevant pages from the 1931 edition.
>
>
>
> Thanks,
>
>
>
> --
>
> Dan-George Uza
>
>
>
>
> <https://www.avast.com/sig-email?utm_medium=email_source=link_campaign=sig-email_content=webmail>
>
> Virus-free. www.avast.com
> <https://www.avast.com/sig-email?utm_medium=email_source=link_campaign=sig-email_content=webmail>
>
>
>
> ---
>
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
>
>
>
> ///workers.exist.lookout
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Analemma intersection

[Roger Bailey]

Hi Dan,
To me the value of the EQT at the intersection is an indication of the 
asymmetry of the analemma caused by the difference between the solstice and 
perihelion dates. The tilt of the earths axis is one parameter that defines the 
analemma. This is shown at the extremes, the summer and winter solstices. The 
eccentricity of the orbit is the other parameter that defines the analemma. 
This is indicated by the perihelion. If the date of the perihelion is the same 
as the solstice, I would expect the curve would be symmetrical and the EQT at 
the intersection would be equal to zero. Perihelion was 2 Jan 2018 and the 
winter solstice was 21 Dec 2018. This 12 day difference defines the offset of 
the intersection of the analemma loops. When was the perihelion on the winter 
solstice? The perihelion changes in a cycle of 25,800 years. So 12 days gives 
12/365.25x25,800 or 878 years ago. In 1140 AD I would expect a symmetrical 
analemma.

Of course there is more to this than this simple approximation of orbital 
dynamics. What was the actual date when the perihelion and solstice were the 
same? I offer this as quick answer to the question on the significance of the 
analemma curve intersection.

Regards, Roger Bailey
Walking Shadow Designs


From: Dan-George Uza
Sent: Thursday, April 12, 2018 3:46 AM
To: Sundial List
Subject: Analemma intersection


Hello,


Tomorrow the Sun will have reached the point of intersection in the analemma 
8-curve. How do you compute the exact time of intersection (i.e. when both the 
hour angle and the solar declination match for two days)? And does it have any 
special significance?


Dan





---
https://lists.uni-koeln.de/mailman/listinfo/sundial



---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: The Palace Sundial

[Roger Bailey]

Which palace? I found two sundials at Windsor Castle, both in the sun. One is a 
vertical declining  sundial dated 1723 is carved on the south face of the Lady 
Chapel of St Georges Chapel. The other is an armillary in a garden below ther 
the Round Tower. They are waymarked here.
http://www.waymarking.com/waymarks/WMF2Y3_St_Georges_Chapel_Sundial_Windsor_Castle_UK
http://www.waymarking.com/waymarks/WMF2Y6_Armillary_Sundial_Windsor_Castle_UK

Regards,
Roger Bailey
aka arby101ca


--
From: "Richard B. Langley" <l...@unb.ca>
Sent: Tuesday, April 10, 2018 11:19 AM
To: "sundial list" <sundial@uni-koeln.de>
Subject: The Palace Sundial

> The Queen and Sir David Attenborough saw the funny side when they came across 
> a strangely placed sundial in the palace grounds:
> http://www.bbc.com/news/av/uk-43714489/her-majesty-and-the-naturalist-took-a-stroll-around-the-palace-grounds
>
> -- Richard Langley
>
> -
> | Richard B. LangleyE-mail: l...@unb.ca |
> | Geodetic Research Laboratory  Web: http://gge.unb.ca/ |
> | Dept. of Geodesy and Geomatics EngineeringPhone:+1 506 453-5142   |
> | University of New Brunswick   Fax:  +1 506 453-4943   |
> | Fredericton, N.B., Canada  E3B 5A3|
> |Fredericton?  Where's that?  See: http://www.fredericton.ca/   |
> -
>
>
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: This year a probe will be sent through the Sun's corona.

[Roger Bailey]

Hello Michael,

Off topic/ Yes! 

Please get a grip. Do you know the void of outer space? Do you realize the 
immensity of the nuclear fusion reactions fueling the sun. Any probe is 
infinitesimal in comparison.  Do the numbers. This probe is not a violation of 
a sacred place.

Roger Bailey


From: Michael Ossipoff 
Sent: Thursday, February 08, 2018 4:42 PM
To: sundial list 
Subject: This year a probe will be sent through the Sun's corona.




Maybe this is a little off-topic here, but not completely:

.

As you may have heard, a space-probe is scheduled to be launched this month, 
which will pass through the Sun’s corona (which extends much farther out from 
the Sun than it was previously believed to).

.

In other words, NASA is goings to intrusively experiment on the Sun.

.

This is called the “Parker solar probe”.

.
Does anyone else find that objectionable?  Even just on principle, if for no 
other reason?

.

Of course the Sun is the origin and energy-source of the Earth, and therefore 
the physical origin of all life on Earth.   …so we dump our garbage into it?

.

Is there anything that we respect enough to not spit on it?

.

After the probe’s first pass through the corona, I don’t know if will be moved 
out of that corona-traversing orbit. Probably not. If not, the of course each 
passage will slow the vehicle, until it eventually falls into the Sun, meaning 
our garbage becomes part of the sun.

.

Someone told me that the craft might vaporize during its first corona-passage. 
I don’t know if that’s true, but, even if so, it doesn’t change the 
experiment’s object.

.

No, the experiment probably won’t result in an “Oops!”, “Uh-Oh!”, or “Oh Shit!” 
moment.  Probably not. Is “probably not” good enough?

.

But there are times when a small bit of matter, operating in a small part of a 
large object, starts an effect that propagates throughout that larger object. 
No, I’m not saying that’s likely. 

.

The whole justification for the experiment is a lack of knowledge about the 
Sun, and the corona in particular. How much assurance does a lack of knowledge 
guarantee?

But, in any case, see above for other reasons why the experiment is 
objectionable.

.

You go outside. It’s a nice sunny day. The solar-convective breeze is rustling 
the chlorophyll leaves of the green trees.  So, with the warm sunshine warming 
your face, you say, “Ah yes, let’s intrusively experiment on the Sun, and dump 
garbage into it!”

.

Michael Ossipoff
















---
https://lists.uni-koeln.de/mailman/listinfo/sundial

---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Perforated ring dials

[Roger Bailey]

Hi Keith,

I gave a short presentation a few years ago on "Baubles, Bangles and Ring 
Dials". It is only 6 slides, 330 kb but it has some useful information and 
references. One reference is to Helmut Sonderegger's NASS Compendium article on 
'Ring Dials, Farmers Ring" and his "Sonne" program that does ring dials. Here 
is a link to my presentation on my Google Drive. 
https://drive.google.com/open?id=0B14iMmxzLvJWZVpVOTctSk9meDQ

Enjoy,
Roger Bailey
Walking Shadow Designs
N 48.6, W 123.4 


From: Keith E. Brandt, WD9GET 
Sent: Thursday, June 15, 2017 10:37 AM
To: sundial@uni-koeln.de 
Subject: Perforated ring dials


I received a gift of a perforated ring dial recently. Like most mass-produced 
dials, it isn't set up for my latitude. I've tried to find info on these dials, 
but I only see a section in "Sundials: Theory and Construction" talking about 
ones with a fixed perforation. My Google-fu has failed me in locating info on 
the construction of dials with movable perforations (like mine). 

My goal is 2-fold: better general understanding of this type of dial, and 
making alterations to correct this dial for other latitudes. (I do have a 
preliminary correction based on the references I do have, but if I can roll in 
the variable perforation location, I can make it more general.

Any good pointers?


-- 

~~
 Keith E. Brandt, WD9GET
 wd9...@amsat.org

'Christianity and science are opposed…but only in the same sense as my thumb 
and forefinger are opposed - and between them I can grasp everything.' —Sir 
William Bragg (Nobel Prize for Physics- 1915) 

 *This message transmitted with 100% recycled electrons  

xb




This email has been checked for viruses by AVG antivirus software. 
  www.avg.com 
 







---
https://lists.uni-koeln.de/mailman/listinfo/sundial

---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: East/West Vertical Bifilar Sundial

[Roger Bailey]

From: Roger Bailey 
Sent: Sunday, May 28, 2017 9:32 PM
To: Nathaniel Shippen ; sundial@uni-koeln.de 
Subject: Re: East/West Vertical Bifilar Sundial


Hello Nathaniel,

Yes, it is quite doable. Here is a sketch produced with Fer De Vries Zon 2000 
for a bifilar in Honolulu Hawaii, lat 21.3° long 158°, X thread 25, Y thread 
15, dec 85° east of south, Inc 88°.

The sketch was too big for the SML size filter. This is the note without the 
sketch, available on request.  

The red lines show the threads, the black lines are the hour and declination 
lines. Doable? yes. Understandable? no. To understand read the NASS Compendium. 
Here over the last 20 years there are over 60 documents related to bifilar 
sundials: articles, programs, presentations by the giants in the field, Fred 
Sawyer, Rafael Soler Gaya, Dominique Collin, Gianni Ferrari and Fer de Vries. 
Rafael Soler Gaya has designed and commissioned some excellent bifilars based 
on catenary curves and conic sections in Mallorca. See my presentation on 
Sundials in Mallorca here. 
https://drive.google.com/open?id=0B14iMmxzLvJWRkpnSk1jbE5odTg Fred Sawyer has 
published on the origins of bifilar sundial starting in 1978. Fer De Vries 
program is easy to use to show what the lines look like. Alll this information 
is available to all NASS members. see www.sundials.org  

Regards, 
Roger Bailey
Walking Shadow Designs


Sent: Sunday, May 28, 2017 1:35 PM
To: sundial@uni-koeln.de 
Subject: East/West Vertical Bifilar Sundial


I've seen some info on bifilar sundials, and they look very interesting. I 
thought I would try to make a simple one (if that is possible). An east and/or 
west facing vertical dial would be the most useful at my location. Actually the 
surfaces I would be using decline a little south of west and north of east (and 
also recline slightly). I would be sketching in the time marks (Hawaii 
Standard) empirically since I am also some 8 degrees west of the standard 
meridian.


Is this doable? Are the computations for the threads and the point of origin 
for the hour lines fairly simple? If yes I'll dig in and do the necessary 
research, just don't want to be off on an impossible quest.


Thank you in advance for your help!


Nathaniel Shippen





This email has been checked for viruses by AVG antivirus software. 
  www.avg.com 
 







---
https://lists.uni-koeln.de/mailman/listinfo/sundial

---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Sun path polar chart generator

[Roger Bailey]

Hello Dan,

Helmut Sonderegger's Sonne software can generate such a chart. Choose the type 
as "horizontal altitude" and try various options. Sonne is available here.
http://www.helson.at/sun.htm

Regards, Roger Bailey


From: Dan-George Uza 
Sent: Monday, February 27, 2017 12:10 PM
To: Helmut Haase 
Cc: sundial@uni-koeln.de 
Subject: Re: Sun path polar chart generator


Something like this.



​



Dan Uza


On Mon, Feb 27, 2017 at 8:40 PM, Helmut Haase <helmut.ha...@teleos-web.de> 
wrote:

  Hell Dan-George,
  Could you post an example graph how the plot should approximately look like?

  Regards
  Helmut Haase

  -- 
  Am 27.02.2017 15:49, schrieb Dan-George Uza:

Hello,


I'm looking for a freeware solution to generate customizable polar sun path 
charts in vector format. The software should be able to display sun paths for a 
custom time interval (like daily, weekly) and feature analemma curves for 
standard hours. Any help will be appreciated!


Dan Uza   

 

---
https://lists.uni-koeln.de/mailman/listinfo/sundial










---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.7998 / Virus Database: 4756/14035 - Release Date: 02/27/17
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Unusual bi-annual sundial

[Roger Bailey]

Hello Frank,

Thanks for reminding us of Omar Khayyam's calendar based on a 33 year cycle. 
John Dee's implementation of this calendar would reduce the equinox variation 
to 24 hours. At one longitude, 77° W, the equinox would always be on the same 
day. Is this God's Longitude? 

Based on your inspiration and advice 10 years ago, I reviewed Simon Cassidy's 
original historical and mathematical research and Duncan Steel's book "Marking 
Time: The Quest for the Perfect Calendar" He nominated Dee's calendar as the 
greatest invention in two millennia.

I summarized the "long story", an alt-history, in a presentation that Fred 
Sawyer gave at the NASS Conference in 2007. "God's Longitude and the Lost 
Colony of Virginia" It is available at my website here: 
http://www.walkingshadow.info/Publications/GodsLongitude.ppt  a 7 MB pppt file.

This is relevant today as Donald Trump is crowned at God's Longitude, 77° W, 
Washington DC 

Roger Bailey
Walking Shadow Designs 


--
From: "Frank King" <f...@cl.cam.ac.uk>
Sent: Thursday, January 19, 2017 8:33 AM
To: "John Goodman" <johngood...@mac.com>
Cc: "Sundial List" <sundial@uni-koeln.de>
Subject: Re: Unusual bi-annual sundial

> Dear John,
> 
> I wondered when someone would spot that there is a
> whole can of worms waiting to be opened here...
> 
>> Won't the factors that necessitate the addition
>> of a leap day prevent this alignment from
>> happening at exactly 11/11 11:11 every year?
> 
> Quite so.  No doubt you looked at the time-lapse
> video and spotted that the circle of light DIDN'T
> properly centre itself on the Great Seal of the
> United States.  This is surely only one step less
> sinful than being disrespectful to the US flag?
> 
> OK, take a deep breath and see what we are up
> against...
> 
> First we need to be clear what is meant by the
> time 11:11?  I assume this is clock time in
> Anthem, Arizona, and a little research suggests
> they are on Mountain Time there and that they
> don't observe Daylight Saving.  [Just think how
> the whole scheme could be wrecked if they did
> go over to Daylight Saving and the clocks didn't
> go back until after 11 November!]
> 
> To me, their interest is at 18:11:00 UTC but that
> is a detail.
> 
> The big difficulty is that, at this exact time of
> day, the solar declination varies with the leap
> year cycle and there is a steady drift.  As a
> result both the solar altitude and solar azimuth
> vary from one year to the next.  Let's see by
> how much...
> 
> I'll take it that the Geographical Coordinates
> of Anthem are:
> 
>   33° 51' 15" N 112° 7' 30"
> 
> Using GCstudio I determined the following data
> for 10 years starting in 2016, a leap year:
> 
>  2016  -17°41'09"  +36°25'01"  +161°40'45"
>  2017  -17°37'11"  +36°28'55"  +161°39'53"
>  2018  -17°33'13"  +36°32'52"  +161°39'05"
>  2019  -17°29'12"  +36°36'55"  +161°38'33"
>  2020  -17°41'38"  +36°24'36"  +161°41'11"
>  2021  -17°37'47"  +36°28'23"  +161°40'14"
>  2022  -17°33'48"  +36°32'21"  +161°39'31"
>  2023  -17°29'52"  +36°36'14"  +161°38'36"
>  2024  -17°42'18"  +36°23'55"  +161°41'16"
>  2025  -17°38'23"  +36°27'48"  +161°40'23"
> 
> The four columns show: year, declination, alt, az
> as they are at Anthem at 11:11:00 Mountain Time
> on 11 November in the 10 years shown.
> 
> Take declination first.  You see that starting in
> 2016 the declination gets about 4 minutes less
> negative on successive years until there is a
> sudden jump back which is A LITTLE TOO BIG.
> This sets the pattern.  We become less negative
> until 2024 when there is another jump.
> 
> The jumps back over-compensate because the tropical
> year is slightly less than 365.25 days.
> 
> You will see that the solar altitude increases by
> just under 4' a year before falling back just over
> 12' in a leap year.  You will see that even in this
> little table the range of altitudes is about 11'
> and this will be noticed by careful observers.
> 
> The azimuth varies too of course but by not so
> much and its main effect is to make you have to
> worry about just how to align the slabs.
> 
> OK, what should they have done?
> 
> Well one approach is to settle on the 2016 figures
> and note that over the next 36 years the data for
> 2016 will be somewhere near the middle.  After
> that the drift will become more noticeable but the
> designer will probably be dead and won't care.
> 
> Things gradually get worse and w

Re: Re[2]: Leap Second Quiz Question

[Roger Bailey]

Hello Mike and all,

I expect the impoundment of water in hydro power reservoirs adds mass to 
northern hemisphere. This would effect the rotation of the earth adding a 
bit of wobble like an out of balance top. Perhaps this wobble could affect 
precession in the long run. Tidal power? Not so much as net storage of water 
is small, following the tides, up and down in a daily cycle.


One way to model tidal power is as an alternating inductive capacitance 
circuit. The resonance of that circuit can create large tidal ranges in 
specific basins like the Bay of Fundy with tides over 20 ft. A large tidal 
power project there would detune that resonance resulting in less power than 
expected and water surging towards Boston rather than Fundy. One study of 
the resonance predicted a rise in the tide level in Boston harbour by 10 cm 
(4"). I am quoting what I remember from a conversation with a tidal power 
expert about 15 years ago so my numbers may be off but resonance of tuned 
inductive capacitive circuits was the basis of the analysis.


"Time and Tide Wait for Gnomon"

Roger Bailey

--
From: <jmikes...@ntlworld.com>
Sent: Sunday, January 01, 2017 7:20 AM
To: "Frank King" <f...@cl.cam.ac.uk>; <sundial@uni-koeln.de>
Subject: Re[2]: Leap Second Quiz Question


Frank wrote:
<>

I was at a talk recently by a guy who was promoting the use of tidal 
energy.

(You know what you are going to get every day was his main theme"

At the end he invited questions, so I asked if the generation of 
electricity by the use of tidal power would slow down the earth or moon.

He looked nonplussed.
I guess it might - comments welcomed.

Mike Shaw
53º21' N  3º02'W


---
https://lists.uni-koeln.de/mailman/listinfo/sundial



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.7924 / Virus Database: 4739/13681 - Release Date: 12/31/16


---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Are there some Sundial Designers, in INDIA ?

[Roger Bailey]

Hello Frank and all,

Consider the third dimension, elevation

Google maps show the view from space of the plane (X,Y). Go to Google street 
view for pictures showing the elevations (Z). The ring road around the 
sundial is a flyover on piers for traffic going south east turning and 
merging to head west. Street view pictures show lots of access for people 
and cars under the flyover. People live there, work there, trying to eke out 
a living.


Consider the fourth dimension, time. One street view picture shows the 
incomplete flyover ending abruptly at a sign announcing the 2010 
Commonwealth games. How has this site changed with time? How do people 
observe time as they rush around the flyover ring? Perhaps this explains the 
strange morning hour lines on the sundial accommodating people rushing past, 
the kind of people that set their clocks ahead so they can avoid being late, 
people that believe daylight savings time is useful.


The Institute of Driving and Traffic Research is across the road. Perhaps 
this sundial is a research project on the time space continuum of Delhi's 
roads and traffic.


In any case, celebrate the return of the sun, the winter solstice at 10:44 
UTC 21 Dec 2016.


Best Regards, Roger Bailey



--
From: "Frank King" <f...@cl.cam.ac.uk>
Sent: Tuesday, December 20, 2016 12:31 AM
To: "Maes, F.W." <f.w.m...@rug.nl>
Cc: "Sundial Mailing List" <sundial@uni-koeln.de>
Subject: Re: Are there some Sundial Designers, in INDIA ?


Dear Frans,

I was interested and amused by your comments
on the Delhi sundial...


According to the newspaper article...


Huh!  I live by two simple rules:

 1. Never believe anything you read in
Newspapers without checking.

 2. Never believe anything you read
anywhere else without checking.

I really ought to have a rule "1a" which
is "to be especially careful of newspapers
published in India."  They seem very prone
to exaggeration: the suggestion that this
dial is "one of the largest scientifically
accurate sundials in the world" is typical!

 This sundial most certainly does not
 merit the attribution "accurate".

It seems to me to be flawed in many
respects.  Most recent photographs
taken in the city seem to show a
very murky atmosphere: this sundial
rarely sees the sun!

The site is almost inaccessible
and it is a really good joke that,
surrounding this sundial, there are
many seats for people to sit on!
These seats will never be used
until there is a helicopter
service!

Very best wishes

Frank

---
https://lists.uni-koeln.de/mailman/listinfo/sundial



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.7924 / Virus Database: 4739/13617 - Release Date: 12/19/16


---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: New York Times - Today will be the earliest sunset of the year.

[Roger Bailey]

Thanks Bob for this link. This date may be true for NYC but the date varies 
with latitude. It is 7 Dec for NYC at 40.7° but 28/29 Nov for Miami at 25.7° 
and 10 Dec where I live in Sidney by the Sea BC at 48.6°. Some time ago I 
developed a spreadsheet to calculate sunrise and sunset times. Input the 
location, Lat and Long, and the starting date and the spreadsheet calculates 
the equation of time, declination rise and set times for a two month period. 
The results for my location are plotted in the chart attached, a 25 kb file. 
The spreadsheet is too big at 87 kb to attach but I would be happen to send it 
to anyone for their use. 

Helmut Sonderegger programmed the equation of time and declination algorithms 
in a spreadsheet  that I imported into this spreadsheet for these calculations. 
It works well to show what happens around the solstice.

Regards, 
Roger Bailey
Walking Shadow Designs



From: Robert Terwilliger 
Sent: Wednesday, December 07, 2016 6:34 AM
To: sundial@uni-koeln.de 
Subject: New York Times - Today will be the earliest sunset of the year.


http://www.twigsdigs.com/annex/sunset.html

 

Bob

 






---
https://lists.uni-koeln.de/mailman/listinfo/sundial




Solstice Rise Set.doc
Description: MS-Word document
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Solar Declination

[Roger Bailey]

Hi Helmut,

Thanks for this feedback. When you send something out, you never know how it 
was received without such feedback. 

Date formats are difficult with Excel. What works on my version, 2003 Canada, 
obviously does not work on yours. Helmut Sonderegger did a lot of debugging to 
make the original spreadsheet international but copy/paste often does not carry 
forward the format. The format I used for column A was date and time. Only date 
was exposed. Column E needed to read the A format as a number and calculate the 
time from the 2000 epoch. They need to be in the same format. I cannot solve 
this from here as the format works for me with my version of Excel. In Europe 
and even the US the formats are different. Different versions of Excel do not 
communicate. The math works which is why non spreadsheet options are sometimes 
better. But I was answering a question specific to a free spreadsheet 
calculation, which I provided.

Regards, Roger Bailey 

From: Helmut Haase 
Sent: Wednesday, October 26, 2016 12:07 PM
To: Roger Bailey ; sundial@uni-koeln.de 
Subject: Re: Solar Declination


Hi Roger,
I had to change the date format in colum A and in the formula of colum E. Maybe 
this is of concern for others too.

It is a matter of taste of course to use a spreadsheet for this calculation. I 
would prefer and recommend a free numerical software like Scilab e.g.. Meeus's 
algorithm would appear readable and edits are easy to make.

Regards, Helmut Haase
- 
Am 26.10.2016 19:05, schrieb Roger Bailey:

  Hi Dan,

  The advice you have received from Gian and others is excellent. I use his 
"Sol et Umbra" android app in a smartphone and tablet. It is a great app. 

  But you asked for a spreadsheet. Attached is one implementation of Meeus's 
simplified solar coordinate calculation. Helmut Sonderegger developed this and 
added it to my spreadsheet for calculating analemmatic sundials. I have copied 
it into several other spreadsheets whenever I needed declination and the 
equation of time. This is a reduced version small enough to get through the SML 
size filter. Input the start date and time into cell A7. Change the increment 
from 1 day to whatever in cell A8. Copy row 8 and paste it in below for as many 
rows as you wish. Copy the spreadsheet into other spreadsheets using solar 
coordinates but be aware of the absolute address to the degree to radian 
conversion in row 1 

  I answered this question about a year ago for Jack Aubert. he was interested 
in the rate of change of declination near the equinox and solstice. I sent him 
a full implementation of that included calculating and plotting the time of 
sunrise near the winter solstice. The copy to the SML was filtered out but I 
will forward his note and my reply with the original spreadsheet.

  To answer this question I needed to review Meeus's Astronomical Algorithms, 
specifically Chapter 25 Solar Coordinates pg 163-170. This great reference book 
is now available as a free download. Just Google Meeus Astronomical Algorithms 
free. Is this an example of fair use, a single copy of a library  copy or a 
copyright violation? I don't know but I was glad to find it. meeus discusses 
the accuracy of the simple calculation compared to the more rigorous version. 
For sundials the simple version is fine.

  Regards, Roger Bailey


  From: Dan-George Uza 
  Sent: Tuesday, October 25, 2016 9:38 AM
  To: sundial@uni-koeln.de 
  Subject: Solar Declination


  Hello,


  Can you provide a free accurate spreadsheet for the calculation of daily 
solar declination across a leap year as well as non-leap year?


  Thanks,


  Dan Uza


--
  ---
  https://lists.uni-koeln.de/mailman/listinfo/sundial




--

  No virus found in this message.
  Checked by AVG - www.avg.com
  Version: 2016.0.7859 / Virus Database: 4664/13266 - Release Date: 10/24/16


   

---
https://lists.uni-koeln.de/mailman/listinfo/sundial



No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.7859 / Virus Database: 4664/13279 - Release Date: 10/26/16
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Solar Declination

[Roger Bailey]

Hi Dan,

The advice you have received from Gian and others is excellent. I use his "Sol 
et Umbra" android app in a smartphone and tablet. It is a great app. 

But you asked for a spreadsheet. Attached is one implementation of Meeus's 
simplified solar coordinate calculation. Helmut Sonderegger developed this and 
added it to my spreadsheet for calculating analemmatic sundials. I have copied 
it into several other spreadsheets whenever I needed declination and the 
equation of time. This is a reduced version small enough to get through the SML 
size filter. Input the start date and time into cell A7. Change the increment 
from 1 day to whatever in cell A8. Copy row 8 and paste it in below for as many 
rows as you wish. Copy the spreadsheet into other spreadsheets using solar 
coordinates but be aware of the absolute address to the degree to radian 
conversion in row 1 

I answered this question about a year ago for Jack Aubert. he was interested in 
the rate of change of declination near the equinox and solstice. I sent him a 
full implementation of that included calculating and plotting the time of 
sunrise near the winter solstice. The copy to the SML was filtered out but I 
will forward his note and my reply with the original spreadsheet.

To answer this question I needed to review Meeus's Astronomical Algorithms, 
specifically Chapter 25 Solar Coordinates pg 163-170. This great reference book 
is now available as a free download. Just Google Meeus Astronomical Algorithms 
free. Is this an example of fair use, a single copy of a library  copy or a 
copyright violation? I don't know but I was glad to find it. meeus discusses 
the accuracy of the simple calculation compared to the more rigorous version. 
For sundials the simple version is fine.

Regards, Roger Bailey

  
From: Dan-George Uza 
Sent: Tuesday, October 25, 2016 9:38 AM
To: sundial@uni-koeln.de 
Subject: Solar Declination


Hello,


Can you provide a free accurate spreadsheet for the calculation of daily solar 
declination across a leap year as well as non-leap year?


Thanks,


Dan Uza





---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.7859 / Virus Database: 4664/13266 - Release Date: 10/24/16


SolarEphem.xls
Description: MS-Excel spreadsheet
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Using linkages to draw curves on sundials

[Roger Bailey]

Hi Tony,

Thanks for your note on Neville Shute and the engineering principle that you 
cannot push a rope (or chain). I have read and reread all of Neville Shute's 
books, the most famous being "On the Beach". My favourite is "No Highway" about 
a boffin studying metal fatigue in aircraft. His actions causing a hard 
grounding of the plane was based on based his esoteric research. This book was 
written around the time of the Comet crashes due to metal fatigue and the 
stress risers in the corners of the square windows in the Comet. At the NASS 
conference in Portland ME, we were described in the media as "boffins". I took 
no offence but recognized it as an apt description recognizing that our arcane 
abstruse interest sometimes leaves people bemused.

Regards, Roger Bailey 

From: tonylindi...@talktalk.net 
Sent: Friday, September 09, 2016 1:58 AM
To: john.pick...@bigpond.com ; Sundial List 
Subject: Re: Using linkages to draw curves on sundials


Hi John,

This query immediately brought to mind an interesting aside from the 
autobiography of Neville Norman, who wrote novels under the pen-name of Neville 
Shute, as he did not wish to trivialize his main profession as an aeronautical 
engineer.  Working in the team of Dr. Barnes Wallis designing the airship R100, 
(the successful commercial opponent of the fatal government-controlled R101), 
he was given the job of stressing its 16-sided lightweight polyagonal frames, 
held rigid by wires.  

Working in pairs, to avoid careless inputs to their mechanical calculators, 
they would take many weeks to assess the stress pattern of each assembly of 
girders and wires based on an initial assumption.  When, after much tedious 
labour, they found that one of the wires based on their first proposal was 'in 
compression' (have you ever tried pushing a chain?) he said "We would moisten 
our lips and begin all over again".  Electronic computers would have achieved 
the ultimate solution to this problem in microseconds both almost within my 
lifetime.

http://www.century-of-flight.net/Aviation%20history/coming%20of%20age/R101%20disaster.htm


  Original Message
  From: john.pick...@bigpond.com
  Date: 07/09/2016 0:14 
  To: "Sundial List"<sundial@uni-koeln.de>
  Subj: Using linkages to draw curves on sundials

  Good morning,

  While researching mechanisms of wire strainers used to tighten wires in 
  fences, and trying to find the theoretical mechanical advantages of the
  different mechanisms, the first thing I learned was that "linkages" are the 
  key to many of them. There's a whole branch of mechanics devoted to the
  theory of these things which involve a zillion combinations of pivots and 
  links to achieve various purposes, usually to transmit motion in a specific
  manner.

  The best explanation I found was Slocum, A. (2008). Fundamentals of design. 
  Topic 4. Linkages
  
(http://web.mit.edu/2.75/fundamentals/FUNdaMENTALs%20Book%20pdf/FUNdaMENTALs%20Topic%204.PDF).
 
  3.3 MB

  But my curiosity lead me further, to a more mathematical treatment. 
  Unfortunately and for unknown reasons, the Jefferson Lab Library has removed 
  the title page.
  Bizarre! I contacted the library and they gave me the full title etc.

  Svoboda, A. (1948). Computing mechanisms and linkages. MIT Radiation 
  Laboratory Series, Volume 27. New York, McGraw-Hill.
  (https://www.jlab.org/ir/MITSeries/V27.PDF) (CAREFUL: 40.8 MB)

  Among other things, this book shows how you can use mechanical linkages of 
  various forms to draw the curves of mathematical functions. And seeing that
  the curves on sundials are all defined by equations, I was wondering if 
  anyone knows of any attempts to make a mechanical device of links and pivots
  specifically for generating sundial equations, and thus drawing sundials? It 
  seems to be a feasible but complicated way of doing it, with some serious
  mathematics behind the linkages.

  I don't include sundial rulers in this, as they are not physically linked 
  and pivotted. Similarly, I don't include CNC machining as this involves 
  moving the tool / work using a pre-programmed series of x, y and z 
  coordinates. And of course, 3-D printing is out.

  (And I still haven't figured out what sort of linkages are used in the wire 
  strainers I'm studying!)

  Cheers, John

  John Pickard
  john.pick...@bigpond.com 

  ---
  https://lists.uni-koeln.de/mailman/listinfo/sundial



---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: The Brightest Part of a Shadow is in the Middle

[Roger Bailey]

Hi Dan-George and all,

I enjoyed the video. Diffraction is of interest but rarely relevant to 
sundialists . We are more concerned with the fact that the sun is not a point 
source but a bright disc half a degree across. We are concerned about the dark 
full umbra when the sun is totally blocked and the penumbra when only part of 
the sun is blocked. This limits the accuracy of sundials, too many shades of 
grey. Various shadow sharpeners help define the shadow by reducing the solar 
disc to a point but merging penumbral shadows remain a problem. I described 
this in a SML email about 17 years ago in a note on penumbral head swelling. 
See https://www.mail-archive.com/sundial@uni-koeln.de/msg03186.html

The phenomenon is easily explores with a finger shadow experiment. Hold your 
hands so your opposed pointing fingers cast shadows. Observe how the gap 
between the shadows disappears long before your fingers touch as the shadows 
swell to fill the gap. The two penumbral shadows merge to create full shadow 
long before the fingers touch. This is why sundials depending on a gap can give 
varying results, A gap between two sharply defined point does not give the 
expected shadow resolution as the penumbral shadows merge. Do the experiment 
see the penumbral swelling effect. 

Regards, Roger Bailey


From: Dan-George Uza 
Sent: Friday, September 09, 2016 11:05 AM
To: sundial@uni-koeln.de 
Subject: The Brightest Part of a Shadow is in the Middle


Hello, what a fascinating video this is!


https://www.youtube.com/watch?v=y9c8oZ49pFc





Dan Uza
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Re: Double analemma dials

[Roger Bailey]

Hi Tony,

Perhaps you are right. All David Andersson's emails have the sunclocks.com as 
the source listed in the headers. Here is a typical clip

Regards, Roger

"Received: from A7000.A7000.sunclocks.com ([2.96.206.108])
 by smtp.talktalk.net with SMTP
 id aqldbkrorfn7DaqlebC0JD; Fri, 19 Aug 2016 21:51:55 +0100
X-Originating-IP: [2.96.206.108]
Date: Fri, 19 Aug 2016 16:43:41 -0500
From: David Andersson 
To: "


From: tonylindi...@talktalk.net 
Sent: Friday, August 19, 2016 3:07 PM
To: sundial@uni-koeln.de 
Subject: Re: Re: Double analemma dials


Could I be forgiven for thinking that "Mr Douglas Hunt"  has re-invented 
himself as one "David Andersson"?
There is a familiar ring about the tone of recent communications??

Mossny Tone



---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Sombrero as a sundial

[Roger Bailey]

Hi Larry and all,

When I looked at the sombrero picture I immediately thought of the Cosine 
Effect on solar intensity. Consider the length of the shadow of the cone on the 
brim. The longer the shadow the lower the intensity of the sun on the plane of 
the brim. By how much? By the cosine of the angle from the normal axis of the 
cone. To calculate this consider the sombrero as a reclining declining sundial 
with a gnomon perpendicular to the plane. The angle (theta) of the shadow from 
the perpendicular  is the ATan of the length of the shadow divided by the 
height. The solar intensity is proportional to Cos theta that angle as the suns 
rays are spread over a larger area than the circular sombrero.

Every time our Mexican friend puts down his hat, he is showing us the relative 
solar intensity at that point. The sun bearing down directly causing no shadow 
is most intense with heating IR and burning UV rays. If the sun is at a lower 
angle, casting a longer shadow due to the time of day or latitude, the 
intensity is lower by the cosine of the shadow angle from the cone. He could 
draw rings on the brim to indicate the relative intensity and drop his hat on 
any surface to check the intensity.

I have used this sundial science to advise a neighbour considering solar 
panels. Charts of intensity for various orientations, tilt and direction 
allowed him to determine the optimum and what to expect at different times of 
day and seasons of the year. Maybe he will save his money and go to Mexico for 
the winter instead of installing solar panels.

Everything I need to know I learned from sundials.

regards, Roger Bailey


From: Larry Bohlayer 
Sent: Wednesday, August 17, 2016 3:44 PM
To: sundial@uni-koeln.de 
Subject: Sombrero as a sundial


This sombrero is a reminder that we should all wear sundial hats to our next 
meetings. 20 points for the heaviest version. 50 for wearing it on the plane.


I am sure that someone has perfected the idea into time readable fashion. A 
modified version with a "wakeup hole" to let the sunlight through to one's skin 
might actually work.


This shortened url takes you to the Adobe Stock Photo website for the titled 
image of "Mexican man having siesta" by Rafael Ben-Ari. Stock#42495149.


https://goo.gl/CFwZNy







Larry Bohlayer
35.4N, 80.7W








---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.7752 / Virus Database: 4647/12827 - Release Date: 08/17/16
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Sunsweep sculpture

[Roger Bailey]

Hi Steve,

Good spotting! Thanks for the posting. I am pleased to see the sculptor 
donated these pieces over 30 years ago. I would not want to pay for them 
through a government grant. They are simple granite slabs aligned east west 
swooping up east to west on the east coast, two triangle  mid continent and 
curved west to east on the west coast. Yes, the sun rises in the east and 
sets in the west, duh!
Here are pictures of the other locations. 
http://scenethroughmyeyes.blogspot.ca/2014/03/sunsweep.html


Regards, Roger Bailey

--
From: "Steve Lelievre" <steve.lelievre.can...@gmail.com>
Sent: Tuesday, August 16, 2016 5:18 PM
To: "Sundial Group" <sundial@uni-koeln.de>
Subject: Sunsweep sculpture


Hello,

Has anyone encountered the set of sculptures called Sunsweep by David 
Barr? It consists of three pieces at sites along the Canada-USA border 
(Campobello NB, Point Roberts WA, Lake of the Woods, MI) and together they 
are meant to represent a conceptual arch symbolizing friendship between 
the two nations. The 3 sites are geographically interesting - they are 
reachable by land from the main part of their respective countries only by 
travelling through the other country (pene-enclaves).


I was recently at Point Roberts and saw the piece located there.. There is 
a plaque indicating that the piece is aligned to the North Star, the 
equinoxes and the solstices. I found that the plane of the slab forming 
the sculpture is aligned East-West but I could not see anything that 
matches the other directions mentioned. Am I missing something? Perhaps 
the shape causes a special shadow on the special dates?


You can find photos on the Web, for example at
http://2.bp.blogspot.com/-t9hlFDU5te0/UzWerhh1YLI/mQg/7gPHFqa8TFw/s1600/Pt+Roberts+Sunsweep.JPG

The outer (upper) curved edge has a curious V profile, with the point of 
the V switching from one side of the slab to the other as it progresses 
over the length of the curve.  The inner or lower curved edge appears to 
be perpendicular to the plan of the slab.  I could not see any markings on 
the ground. To me, placement of the ring of stones around the base appears 
insignificant.


Any thoughts?

Steve




---
https://lists.uni-koeln.de/mailman/listinfo/sundial



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.7752 / Virus Database: 4647/12819 - Release Date: 08/16/16


---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Sundials and Pokémon

[Roger Bailey]

The valuable content in Tony's email to the SML is quoted below.

"I've just received some nice pictures of the reproduction of a 1773 dial made 
originally by Heath and Wing of London which was re-delineated in 2010 for its 
new home at Holland College on Prince Edward Island in Canada showing six years 
of interesting patination. A footnote accompanying the pictures tells me that 
the dial has become a prominent feature of the campus but there is now a 
'Pokemon Go' creature to be found dancing on it. Ouch!  Tony Moss"

I have witnessed several young people playing Pokémon Go around town. Perhaps 
we can take advantage of this phenomenon and increase peoples interest in 
sundials by encouraging sundials as Pokémon locations. Precise locations are 
available on the web in various sundial registries world wide. 

Perhaps we could nominate the the "slithy tove" as a wild Pokémon character and 
the wabe as a Pokémon cell or gym. An image of a "slithy tove as it did gyre 
and gimble in the wabe is here. 
https://upload.wikimedia.org/wikipedia/commons/4/43/Jabberwocky_creatures.jpg 
Humpty Dumpty reported that "Toves are something like badgers, they're 
something like lizards, and they're something like corkscrews. Also they make 
their nests under sun-dials, also they live on cheese." Perhaps the Pokémon 
toves in the southern hemisphere would have counter rotating corkscrew tails. 

Should we forward this modest proposal to the Pokémon developer "Niantic Inc" 
in California or the "Pokémon Company" in Japan for implementation?

Roger Bailey
Walking Shadow Designs
Sidney by the Sea BC ---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Sawyer Dialing Prize 2016

[Roger Bailey]

Roger Bailey is pleased to have receive the NASS Sawyer Dialing Prize for 2016. 
The certificate recognizes Roger for "consistently showing the dialing 
community that all you need to know in life can be learned from studying 
sundials, and for using that study to advance the theory and practice of 
dialing." For details see 
http://sundials.org/index.php/features/sawyer-dialing-prize 

On receiving the award Roger's presentation was "That is a Good Question".  
Here he pointed out that most of his achievements in the art and science of 
dialing was sparked by answering good questions, questions like the shadow 
lengths or the time and direction of sunrise sunset on analemmatic sundials or 
time systems on Islamic sundials. The theme was "Ask and you shall receive". He 
remains open to good questions.

Roger Bailey
NASS Secretary
Walking Shadow Designs---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Amira Willighagen

[Roger Bailey]

Thanks Tony, 
Roger Bailey


From: tonylindi...@talktalk.net 
Sent: Monday, May 23, 2016 2:09 AM
To: Sundial List Sundial List 
Subject: Amira Willighagen


Hi,
 If you are a 'Sundial Messages Only' person PLEASE IGNORE THIS.  For the 
rest of us here are a few moments of pure and absolute delight (Sound on)

www.youtube.com/embed/ZWpLfncliwU?rel=0


Tony Moss






---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.7597 / Virus Database: 4568/12281 - Release Date: 05/23/16
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Tropic of Capricorn sundial

[Roger Bailey]

Hello John, 

Yes, this is a puzzle. The sun on the solstice, 21 June, is at its lowest 
altitude in the southern hemisphere. The noon altitude would be 47°. The sun 
would rise and set on that day farthest to the north. This is an appropriate 
new years day in the southern hemisphere to celebrate the return of the sun as 
our new year in the north starting at the winter solstice. None of these 21 
June observations seem to relate to the "sundial".

However other seasonal markers would be obvious with this sundial. One is the 
winter solstice 21 Dec. On that date at the Tropic of Capricorn the sun at noon 
would be directly above this sundial, casting no visible shadow. This would 
explain the vertical orientation of the gnomon as the shadow could be seen 
getting shorter as noon approaches and longer in the afternoon. 

The sloping east west gnomon could be used to note an approximate midway point 
between the equinox and the solstice. When does the sun line up due east and 
west at an altitude of 23.5°? The equation for the prime vertical, the east 
west meridian, Sin Alt = Sin Dec / Sin Lat. This resolves to Sin Dec = Sin23.5 
x sin 23.5 and gives the declination as -9.15°. The east west sun along the 
line of the sloping gnomon occurs around 17 Oct and 25 Feb. Perhaps these were 
significant dates for the ancient culture in the area. Pre-Christian cultures 
in Europe had such mid-season markers, Samhain 1 Nov and Imbolc 2 Feb. were a 
couple of the names. A residual in Christian cultures is Michaelmas and 
Candlemas  

The gnomon could also indicate the equinoxes as the sun rises due east and sets 
due west in line with the gnomon. For early cultures marking the calendar with 
seasonal markers was much more important than measuring the time of day. 

Regards, 
Roger Bailey


From: John Goodman 
Sent: Sunday, April 24, 2016 8:31 AM
To: Sundial List 
Subject: Tropic of Capricorn sundial


I was recently in northern Argentina at the Tropic of Capricorn. I saw a 
structure there that has been described as a sundial but I have trouble 
understanding how it could work. I'm attaching a small photo of the gnomon, 
which is angled at roughly 23.5 degrees. So far so good. 


What confuses me is that the gnomon is aligned along the east/west axis, which 
you can see by the Google Maps satellite view shown for the coordinates 
23°26'52.1"S 65°21'06.0"W


I've also read this description of the marker, automatically transited from 
Spanish: 


  Generally, this place is chosen so that the natives of here come and 
celebrate the Inti Raymi, thanking the Sun on June 21, as the Incas used to do 
many years ago. They await the arrival of the Sun which for them is a new year.



Would an east/west orientation be appropriate for a monument marking the June 
solstice south of the equator?


Thanks for your help deciphering the design,
John









---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.7539 / Virus Database: 4556/12091 - Release Date: 04/24/16
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Sundials in museums

[Roger Bailey]

Hi Darek,

Participating in NASS and BSS conferences over the past 20 some years has 
provided the opportunity to some amazing collections of historical 
scientific instrument. Here are a few that I have had the opportunity to 
visit , two in the USA and two in the UK. All were worth the trip.


Harvard University Collection of Historical Scientific Instruments. 
https://chsi.harvard.edu/index.html
Contact Dr. Sara Schechner, the David P. Wheatland Curator of the Collection 
of Historical Scientific Instruments


Adler Planetarium, Chicago  http://www.adlerplanetarium.org/ or specifically 
astronomy in culture 
http://www.adlerplanetarium.org/events/astronomy-in-culture-2-2016-01-10/


Cambridge University, Museum of the History of Science. 
http://www.hps.cam.ac.uk/whipple/ An remarkable collection of sundials and 
astronomical instruments


Royal Museums Greenwich, Astronomical and navigational instruments. The 
National Maritime Museum (NMM) holds a large and varied collection of 
astronomical and navigational instruments, 3587 items. These range from 
astrolabes and armillary spheres to quadrants, nocturnals and sundials. 
http://collections.rmg.co.uk/collections.html#!csearch;authority=subject-90227;browseBy=collection.


This is my short list. There are many others worth exploring.
Regards, Roger Bailey

--
From: "Darek Oczki" <dhar...@o2.pl>
Sent: Saturday, January 09, 2016 4:54 AM
To: <sundial@uni-koeln.de>
Subject: Sundials in museums


Hello
I wish everyone on this list plenty of sunshine in the 2016.

I've got a question. Is there a list/register of sundial collections in 
museums arround the world? I would like to ask your advise which ones are 
worth visiting.


During Christmas I was in Milano, Italy and as they were open I visited 
the Poldi Pezzoli Museum to see what sundials they got. I found out they 
have a very nice collection consisting of 200 pieces of all kinds of 
portable sundials including a Navicula and 2 canon dials. I took a lot of 
photos.


What other places would you recommend?

--
Best regards
Darek Oczki
52N 21E
Warsaw, Poland
GNOMONIKA.pl
Sundials in Poland
http://gnomonika.pl
---
https://lists.uni-koeln.de/mailman/listinfo/sundial



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.7294 / Virus Database: 4489/11357 - Release Date: 01/08/16


---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: dodecahedron

[Roger Bailey]

Thanks Fabio and Riccardo,

This is really cool. It makes the design so easy, that it almost feels like 
cheating. Consider the classic painting by Holbein of Kratzer working on a 
simpler polyhedron and not getting it right. See 
https://www.oneonta.edu/faculty/farberas/arth/Images/Ambassadors/holbein_kratzer_polyhed.jpg
 

Regards, Roger Bailey


From: Fabio nonvedolora 
Sent: Tuesday, January 05, 2016 7:59 AM
To: sundial@uni-koeln.de 
Subject: dodecahedron


Hi all

Riccardo Anselmi, an italian gnomonist, uploaded a new paper sundial, the app 
47 (www.sundialatlas.eu/atlas.php?app=47), it is a dodecahedron inspired to a 
sundial in Palermo, Sicily, IT619.

Enjoy it, ciao Fabio

Fabio Savian
fabio.sav...@nonvedolora.it
www.nonvedolora.eu
Paderno Dugnano, Milano, Italy
45° 34' 10'' N, 9° 10' 9'' E, GMT+1 (DST +2)





---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.7294 / Virus Database: 4489/11323 - Release Date: 01/04/16
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Diamond Fuji

[Roger Bailey]

Hi Dan,

Our NASS member in Japan, Barry Duell, gave a presentation a few years ago on 
the Fuji Diamond. This inspired me to observe and take pictures from my home of 
sunrise over Mt Baker. This glaciated volcanic peak 10,781 ft or 3286 m high is 
about 100 km across the Salish Sea from my home in "Sidney by the Sea" BC. 
Conditions were perfect on 1 April 2013, clear skies and a solar declination of 
4.6° and sunrise azimuth of 83°. The pictures of this Mt Baker Diamond are here.
 
https://picasaweb.google.com/rtbailey101/MtBakerDiamond?authuser=0=Gv1sRgCJCXqrr1qqWyFw=directlink.
 
The moonrises here are equally spectacular. 

Best Wishes for 2016,

Roger Bailey


From: Dan-George Uza 
Sent: Monday, January 04, 2016 1:04 PM
To: sundial@uni-koeln.de 
Subject: Diamond Fuji


Hello,


I saw a news report today about “Diamond Fuji”. When the sun appears to rise or 
set on top of Mount Fuji in Japan it shines like a diamond. 



http://newsonjapan.com/html/newsdesk/article/114827.php



-- 

Dan ​ Uza






---
https://lists.uni-koeln.de/mailman/listinfo/sundial






---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Ciudad Mitad del Mundo re sundial digest volume 120 issue 9

[Roger Bailey]

I think the site of interest is Quitsato as it is right on the equator. 
https://en.wikipedia.org/wiki/Quitsato_Sundial

Two NASS members have visited the site and given presentations at NASS 
conferences, Will Grant in 2013 and Dean Conners in 2014. Here are quick 
summaries from the Conference Retrospectives.

2013 My Pilgrimage to Quitsato: Will Grant described his visit to the middle of 
the world, Quitsato, Ecuador (0.000°N, 78.1750°W). At Quitsato a large vertical 
pillar sundial casts shadows on the Andean Cross, a pattern with the diagonals 
crossing the center at 23.5° from the equator and meridian. He visited the site 
several times to observe the sunrise, sunset and midday shadows. He saw a 
similar sundial at San Paulo and a 3-D Andean Cross at Cotacachi. The concept 
of the equator and the path of the sun was well known in ancient cultures in 
South America. Further evidence was a pre-inca pyramid he visited. The walls 
had slopes of 23.5° and 47°.

2014 “Quitsato” Dean Conners told of his recent trip to Quitsato, an 
“Ecuadorian Equatorial Equinoctial Excursion” to observe the pillar sundials 
casting no shadow at noon on the equinox. 

Regards, Roger Bailey


From: Dennis Cowan 
Sent: Thursday, December 10, 2015 1:26 AM
To: Sundial List 
Subject: Ciudad Mitad del Mundo re sundial digest volume 120 issue 9




This is the Wikipedia article on the site north of quito


https://en.wikipedia.org/wiki/Ciudad_Mitad_del_Mundo


Dennis Cowan
Sundials of Scotland






Sent from my Mobile





---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.7294 / Virus Database: 4483/11153 - Release Date: 12/10/15
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Gnomon filaris mystery

[Roger Bailey]

Hi Dan,

This looks like the meridian sundial in the astronomy tower of the Clementinum 
in Prague. It is one of about 17 interesting sundials at the Clementinum. See 
http://www.waymarking.com/waymarks/WM86NC_Meridian_Sundial_in_the_Clementunum_Astronomical_Tower_Prague.

Here is my description of the sundial from that waymark. There are several 
photos with the waymark of this "gnomon filaris", a single wire acting as a 
shadow sharpener.

"When you visit the Clementinum in Prague, take the tour of the Astronomical 
Tower. Most do this to enjoy the view over the city but there is an interesting 
if subtle feature in the tower. A small hole in the south facing window at the 
top of the tower projects a bright spot onto a meridian strip on the floor and 
north wall of the room. This strip just below the prominent quadrant with a 
transit telescope is in a long wooden box with protective doors. This meridian 
is marked for the position of the solar spot at noon at different dates and 
solar declinations throughout the year. Just above the meridian strip is a taut 
wire carefully aligned north in the vertical and horizontal axes. 

When the solar spot projected onto the meridian strip is bisected by the wire 
shadow, it is solar noon. Then a flag was waved out of the window to signal to 
the gunners in the castle across the river. They then fired the noon cannon to 
mark Prague Noon. This procedure was established in 1842 and continued until 
1926 although Prague switched to Central European Time in 1912."

Regards, Roger Bailey

aka "arby101ca"

From: Dan-George Uza 
Sent: Sunday, November 29, 2015 9:55 AM
To: sundial@uni-koeln.de 
Subject: Gnomon filaris mystery


Hello,


Catholic bishop Batthyany Ignac established one of the first astronomical 
observatories of Transylvania in Alba Iulia in the late 1700s, with Antonius 
Martonfi - a former Jesuit - serving as astronomer and director. The latter 
published a 400 page book in 1798 entitled "Initia astronomica" which lists the 
observatory's available technical equipments. Among them were two scientific 
gnomons, one of which is said to have been filar (gnomon filaris, gnomon 
filair, meridienne filaire). Today Martonfi's book is rather difficult to come 
by, there once was a copy in Cluj University library, but that has since 
vanished (perhaps it was stolen and sold off to collectors). So far I have been 
unable to gain access inside the Observatory in Alba Iulia and actually see 
what remains of these gnomons, but I managed to obtain a photo showing what 
appears to be a trap door on the wooden floor of the observing room, presumably 
with a cable running underneath up to the wall in the back, ending with a 
suspended weight (see enclosed). I've done some research and it seems this kind 
of sundial was first described by German physicist Christian Gottlieb 
Kratzenstein in 1782. A detailed description and drawing are also available in 
the work "Beschreibung der meteorologischen Instrumente" by Augustin Stark, a 
copy of which can be read here: 
http://www.e-rara.ch/zut/content/titleinfo/6013342 


Have a look at the drawing on the left of Tab. V on page 100. There light 
enters through a 2 mm hole drilled in a metal plate which is fixed outside the 
southern window, parallel to the equator, and the meridian cable runs across 
the roof of the room and also ends in a weight. From it you had to suspend one 
or more vertical wires, the shadows of which caught on a piece of paper were 
used to time solar transits. But contrary to the filar gnomon presented in this 
book, the meridian cable from the old observatory in Alba Iulia appears to run 
UNDER the floor so I am unsure how it was used. The question also arises 
whether there still are any similar working filar gnomons left in other old 
astronomical observatories.


Dan Uza





---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.7227 / Virus Database: 4477/11088 - Release Date: 11/29/15
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Construction of a Hemispherium

[Roger Bailey]

Thanks Frans. This is where the link to Fers's webpage should be. The files I 
provided captured the text but not the two pictures of a plastic bowl 
hemispherium with normal and sidereal hours. your use of the the archive source 
provided these details. Thanks Dan for raising the question. We all benefit 
with this open sharing of information

Regards, Roger Bailey




From: Maes, F.W. 
Sent: Tuesday, September 29, 2015 6:52 AM
To: Dan-George Uza ; Sundial Mailing List 
Subject: Re: Construction of a Hemispherium


Dear all,


Thanks to the invaluable resources of archive.org, Fer de Vries' webpage on the 
construction of a hemispherium could be reconstructed. For convenience I 
uploaded it to: www.fransmaes.nl/zonnewijzers/downloads/hemisph.htm.


Best regards,

Frans Maes



On Mon, Sep 28, 2015 at 9:03 PM, Dan-George Uza <cerculdest...@gmail.com> wrote:

  Dear Frans,


  As far as I can see your message did NOT go to the SML.


  Dan


  On Wed, Sep 16, 2015 at 12:59 PM, Maes, F.W. <f.w.m...@rug.nl> wrote:

Dear all,


Thanks to the invaluable resources of archive.org, Fer de Vries' webpage on 
the construction of a hemispherium could be reconstructed. For convenience I 
uploaded it to: www.fransmaes.nl/zonnewijzers/downloads/hemisph.htm.


Best regards,

Frans Maes



On Tue, Sep 15, 2015 at 2:38 PM, Thibaud Taudin Chabot <tcha...@dds.nl> 
wrote:

  here is the missing picture
  Thibaud

  At 21:25 14-9-2015, Dan-George Uza wrote:

Dear Frans et al.,

Enclosed is the article Roger Bailey sent me. As other people expressed 
interest I wanted to host it on my blog but then I thought: wouldn't it be more 
suitable to appear on a Dutch website? Be warned, a couple of links are still 
missing.

Regards,

Dan Uza

On Mon, Sep 14, 2015 at 12:11 AM, Maes, F.W. <f.w.m...@rug.nl> wrote:

  Hi Dan,


  Fer's message of 1996, still in the archives, said:

  "On the Internet I have made a page with drawings how to construct a 
hemispherium. [...] This page will be removed after some time"

  As you may know, Fer passed away earlier this year. I am afraid that 
the page indeed has been lost, unless someone has downloaded and stored it 
locally.


  The article in the Bulletin of the Dutch Sundial Society 1979, to 
which Fer referred, is available as a scan; in Dutch, 7 pages.


  Best regards,

  Frans Maes


  On Sun, Sep 13, 2015 at 7:57 PM, Dan-George Uza 
<cerculdest...@gmail.com > wrote:

Hello!


I am trying to locate a copy of Fer de Vries' website article 
detailing the construction of a hemispherium sundial. The link was posted here 
in 1996 but it is no longer available. Please help if you can. 


​Dan Uza



---

https://lists.uni-koeln.de/mailman/listinfo/sundial







-- 
Dan-George Uza
http://cerculdestele.blogspot.com
Content-Type: application/zip; name="Hemispherium.zip"
Content-Disposition: attachment; filename="Hemispherium.zip"
X-Attachment-Id: f_iekbbovk0









  -- 

  Dan-George Uza 
  http://cerculdestele.blogspot.com







---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2015.0.6140 / Virus Database: 4419/10720 - Release Date: 09/28/15
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Construction of a Hemispherium

[Roger Bailey]

I have a copy of the webpage and files in a folder. I will send will send these 
files to you individually.

Regards, Roger bailey


From: Dan-George Uza 
Sent: Sunday, September 13, 2015 10:57 AM
To: sundial@uni-koeln.de 
Subject: Construction of a Hemispherium


Hello!


I am trying to locate a copy of Fer de Vries' website article detailing the 
construction of a hemispherium sundial. The link was posted here in 1996 but it 
is no longer available. Please help if you can. 


​Dan Uza







---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2015.0.6086 / Virus Database: 4419/10633 - Release Date: 09/13/15
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Metal cone

[Roger Bailey]

Hello Ray,

The NASS Compendium is the major benefit for NASS members and only available 
to members. Treat my note as an invitation to join. The digital download 
option cost only $20 per year. We are a not for profit society run by 
volunteers. All the membership dues are returned to the members as benefits 
like the Compendium. For details see 
http://sundials.org/index.php/join-nass/join-nass


Here is the article that provides background on the software written by 
Brian Albinson.


Hollander Dial Software
Brian Albinson (North Vancouver, British Columbia, Canada)

I have been interested in sundials ever since I was a youngster, 
particularly in how to read mean time. I
remember seeing a large bronze 19th Century dial, I forget where, which had 
a worm drive on the dial
face with a knob you turned to match the month. At the time I did not 
understand the meaning of EoT.
I graduated in engineering some 56 years ago, in the age of the slide rule 
and 8-figure log tables. There
were (I think) at that time only two computers in England, one (MADAM) was 
in the next building to
where I did my research in the Reynolds Lab in Manchester UK. It had 20,000 
valves (tubes!), occupied
a whole wing and had a mean time between failure of about 5 minutes. I tried 
to figure out how to apply
it to my hydraulic problems but binary and mercury delay lines were beyond 
me. During my subsequent
career I taught myself the elements of simple programming, acquiring the bad 
spaghetti habits of selftaught

programmers; I cannot now follow some of the stuff I wrote.
More recently I saw Fred Sawyer's paper on the Longwood dial and the 
mathematics interested me to the
point where I devised an 'engineer’s' approach to determining the analemma 
coordinates simply by grid
scanning over every possible point on progressively finer grids and choosing 
the point of minimum error.
It turned out that Ken Seidelman had published the algorithm in 1970; I 
really now know how Newton
must have felt about Leibnitz. Actually, there does remain a small feature 
which remains original;
because I wrote in Excel the visual presentation led me to the idea of the 
possibility of distributing the

errors by weighting differently at different times of the year.
When I saw the Hollander Mean Time dial at the recent Vancouver Conference 
(see the articles in The
Compendium 13(3), Sep 2006), I thought it would be an interesting challenge 
to write the software. I
contacted Hendrik who said he was not going to write a program for general 
use so I spent a few days in

the den.
I must extend my thanks to Ben Hoffmann and Warren Thom who took my hand and 
provided a hundred
pages of guidelines on how to produce .dxf files from Visual Basic. Also the 
wonderfully clear and
concise paper by Fred Sawyer. Fred's method of directing the tangent shadow 
to the correct side of the
ellipse, forcing the intersection to be always within the cone shadow, was 
inspirational.
As a footnote, it seems that you only need a relatively small portion of the 
end of the gnomon to be

conical, this could lead to some very artistic interpretations.
The program, provided as part of the digital bonus with this issue of The 
Compendium, comes in a zip
package containing the .exe file and all the .dll run time files needed. 
Just double click and the program
should automatically unpack, load the .exe file into the folder you name and 
the .dll files into your system

folder.
The program is very easy to use and will display the dial face and cone 
development on the screen. In

this mode the dial face and cone development are to different scales.
The Printer option produces scaled output to an 11” x 8.5” paper; the 
printer is scaled to print both the
dial and the cone development to the same scale in both x and y directions; 
but only one scale is available.
The dxf file option produces dial face and cone development output to the 
same scale in different dxf
files. You should choose a file name without the .dxf , the program 
automatically adds the .dxf. You can

use your CAD program to edit the .dxf files and produce any scale you want.

Brian Albinson, 3441 Wellington Crescent, North Vancouver BC V7R 3B3 Canada
brianalbin...@shaw.ca

--
From: Ray flowercity14...@gmail.com
Sent: Wednesday, August 19, 2015 10:42 AM
To: Roger Bailey rtbai...@telus.net
Cc: Dan Uza cerculdest...@gmail.com; sundial@uni-koeln.de
Subject: Re: Metal cone


Hi Roger,

I did a search for NASS Compendium 14-2 Hollander Dial Software;
unfortunately the link to find a DeltaCAD marco was not available or I
missed it, or perhaps you have to be a member of the North American
Sundial Society to access it.  Do you have a direct link to the Marco
for the Hollander Sun Dial?; I am also interested in making one.
Thank you,
Ray
N043., W077.
flowercity14...@gmail.com

On 8/18/15, Roger Bailey rtbai...@telus.net wrote:

Hi Dan,

As you consider conical gnomons, pay

Re: Metal cone

[Roger Bailey]

Hi Dan,

As you consider conical gnomons, pay attention to the conical sundials of 
Hendrik Hollander, the winner of the 2006 Sawyer Award. His conical bi-gnomon 
sundials could tell clock time. Here is the note on his award. 

The 2006 Sawyer Dialing Prize has been awarded to Hendrik Hollander for his 
innovative design of a mean-time planar sundial with oblique conical gnomon and 
modified hour lines and day curves – resulting in a sundial adapted to modern 
timekeeping while retaining the aesthetic appeal of the familiar dial face.

Google his name and sundials to see what his conical sundials can do. A link to 
this article published in the NASS Compendium 13-3 will come up. Also check the 
digital bonus with NASS Compendium 14-2 Hollander Dial Software. 

Regards, 
Roger Bailey
NASS Secretary


From: Dan Uza 
Sent: Saturday, August 15, 2015 11:16 AM
To: sundial@uni-koeln.de 
Subject: Metal cone


Hello all ! 


Any idea how much a metal cone would cost and where to buy it online? The kind 
you can use as gnomon - Ebay has loads of punk spikes on offer, but they are 
too small. 


Thanks!


Dan Uza





---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2015.0.6086 / Virus Database: 4392/10442 - Release Date: 08/15/15
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Temporal Hours

[Roger Bailey]

Hi Jack,

While following a lead based on Sasch Stevens display at the conference, I came 
across an interesting article on the Al Khanum dial by Googling Alexander the 
Great sundial. This search found this article: A Unique Greek Sundial 
Recently Discovered in Central Asia by Rene Rohr in 1980 in the JRASC. The 
article describes the work at Al Khanum by Paul Bernard. See 
http://adsabs.harvard.edu/full/1980JRASC..74..271R Their conclusion is the same 
as yours, the dial is a an equatorial with a polar gnomon but the lines show 
temporal hours rather that straightforward equal hours.

Regards, Roger

From: Jack Aubert 
Sent: Sunday, August 02, 2015 6:55 PM
To: schalda...@aol.com ; rtbai...@telus.net ; email9648...@gmail.com ; 
sundial@uni-koeln.de 
Subject: RE: Temporal Hours


I assume that you are referring to the Arachne of the Amphiareion.  I have a 
photocopy of your article on that dial, which was reconstructed from fragments, 
describing a (very old) horizontal dial with equal hours.  

 

Another atypical dial:  The Ai Khanum dial found in the ruins of Alexandria on 
the Oxus (in modern Afghanistan) that dates from approximately 145 BC is an 
example of a polar-oriented gnomon  with unequal hours.  This dial is 
interesting for several reasons, in particular the fact that while it 
“naturally” told equal hours using the line-shadow of the gnomon,  the 
constructor carefully incised lines to read unequal hours using the gnomon tip. 
  (It was done incorrectly for its latitude, but that’s another story.)

 

However, both these dials are quite exceptional.  My general impression from 
what I have been able to read is that equal hours were used by astronomers and 
astrologers.  While there is at least one example of a horizontal dial that 
uses equal hours and at least one example of a polar gnomon using temporal 
hours, people generally wanted their time in temporal hours so the vast 
majority of surviving dials prior to the Ibn al-Shatir dial used temporal 
hours.

 

Jack Aubert

 
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Temporal Hours

[Roger Bailey]

Hi Michael and all,

I don't know the dominance of temporal hours or equal hours before mechanical 
or water clocks were in common usage. It is clear they co-existed. It is a 
significant research endeavor to determine the dominance and the reasons. 
Meeting for lunch was no problem. Dinner was more chancy; remember the verse of 
Cattulis, Cenabis bene, mi Fabulle. Once the time and location were set, the 
important question remained Who is bringing the duck.

Greek and Roman dials were not horizontal or vertical flat planar dials, but 
hemispheres, scafes or other projections of the sky onto a spherical or conical 
surface.  Planar dials came with the Islamic dials. The first planar dial with 
a polar gnomon was  by Ibn al-Shatir in Damascus in 1371. This dial had  
temporal hours, equal hours based on noon, sunrise and sunset, and Islamic 
prayer times, including reference lines to prayer times when the sun was well 
below the horizon. For me this dial is the epitome of sundials. It includes all 
the time systems in vogue at that time and for hundreds of years before and 
after. They all existed and were in common usage suited for different purposes. 
The question remains Who is bringing the duck for dinner. Time is important. 
Don't overcook it. 

Regards, Roger Bailey


 Michael Ossipoff 
Sent: Wednesday, July 29, 2015 11:57 AM
To: Roger Bailey ; sundial list 
Subject: Re: Temporal Hours


Roger, thanks for the answer. Ok, I shouldn't say that as a fact without having 
more information than I do. This is what I was implying or saying, without 
really having much support for it:


In Europe and the fertile-crescent region, in ancient, classical and medieval 
times, before mechanical clocks (starting with Folliet-balance clocks) came 
into wide use, Equal Hours were of interest, for the most part, only to 
astronomers and astrologers. For ordinary civil timekeeping, for arranging 
meetings, keeping schedules or other civil/social purposes, Temporary Hours 
were preferred by pretty much everyone.



Were a fair percentage of people making their appointments and schedules by 
Equal Hours in the times and places named in the above paragraph?


I'm not being argumentative--I really don't know. 


--


Thanks for reminding me about Temporary Hours lines on Flat Dials being 
satisfactorily approximated by straight lines. I'd temporarily (no pun 
intended) forgotten that. It was a question that I'd asked, and received an 
answer to, when I first wrote to NASS.


Were Flat-Dials (for Temporary or Equal Hours) in use before mechanical clocks 
were getting popular?  What about _wide_ use? How early?


-


Can anyone explain why the early, inaccurate inertia-controlled Folliet-Balance 
clocks replaced the cheaper, more easily-made water-clocks? Were those 
earliest, most inaccurate mechanical clocks significantly, or any, more 
accurate than water-clocks?


Michael Ossipoff












On Tue, Jul 28, 2015 at 11:58 PM, Roger Bailey rtbai...@telus.net wrote:

   Hi Michael  and all,

  Temporal or Antique hours co-existed with equal hours from way back, 
thousands of years. It didn't take a technological device like a clock to cause 
a change. A more interesting point is the portrayal of temporal hours, 12 
unequal hours in the day on a flat sundial. It is easy on Greek/Roman 
hemispheres but what about flat planar sundials. Is it sufficient to calculate 
the points for the solstices and draw a straight line between them? This works 
but is it right mathematically? To answer this question, Fred Sawyer gave an 
excellent presentation on Antique Hours at the NASS Conference in 2010 in 
Burlington. Was it really five years ago! Here is a clip of the abstract from 
the NASS website.

  Antique Hour Lines: Fred Sawyer gave another excellent example of his 
reviews of the history of complex mathematical concepts for sundials. In the 
case of Antique Hour Lines, the question was “Are they straight lines?” For 
millennia they were assumed to be, but the assumption was questioned by many 
mathematicians. Proofs were offered by Ibrahim Ibn Sinan in the 10th century, 
Christopher Clavius in the 16th, Hellingweth in the 18th and many including 
Montucla, Delambre and Cadell in the 19th, offering proofs that the lines were 
in fact curved. The various proofs tended to be empirical based on plotting the 
results of individual calculation. Biot offered an analysis in 1841 and Davies 
in 1843, but the problem was not fully solved until 1914 when Hugo Michnik 
studied the curves for the equatorial sundial, providing a method to come up 
with non-parametric equations for the curve for each hour. Fred then presented 
the graphs of various hour lines at different latitudes and inclinations. The 
curves were amazingly complex looking but the specific area of interest, where 
a shadow would be projected was very close to the straight lines of the 
traditional method

Temporal Hours

[Roger Bailey]

 Hi Michael  and all,

Temporal or Antique hours co-existed with equal hours from way back, thousands 
of years. It didn't take a technological device like a clock to cause a change. 
A more interesting point is the portrayal of temporal hours, 12 unequal hours 
in the day on a flat sundial. It is easy on Greek/Roman hemispheres but what 
about flat planar sundials. Is it sufficient to calculate the points for the 
solstices and draw a straight line between them? This works but is it right 
mathematically? To answer this question, Fred Sawyer gave an excellent 
presentation on Antique Hours at the NASS Conference in 2010 in Burlington. Was 
it really five years ago! Here is a clip of the abstract from the NASS website.

Antique Hour Lines: Fred Sawyer gave another excellent example of his reviews 
of the history of complex mathematical concepts for sundials. In the case of 
Antique Hour Lines, the question was “Are they straight lines?” For millennia 
they were assumed to be, but the assumption was questioned by many 
mathematicians. Proofs were offered by Ibrahim Ibn Sinan in the 10th century, 
Christopher Clavius in the 16th, Hellingweth in the 18th and many including 
Montucla, Delambre and Cadell in the 19th, offering proofs that the lines were 
in fact curved. The various proofs tended to be empirical based on plotting the 
results of individual calculation. Biot offered an analysis in 1841 and Davies 
in 1843, but the problem was not fully solved until 1914 when Hugo Michnik 
studied the curves for the equatorial sundial, providing a method to come up 
with non-parametric equations for the curve for each hour. Fred then presented 
the graphs of various hour lines at different latitudes and inclinations. The 
curves were amazingly complex looking but the specific area of interest, where 
a shadow would be projected was very close to the straight lines of the 
traditional method.

This is why I belong to NASS, to read the Compendium and to go to the 
conferences. Here we see solutions to problems we didn't even know existed.

Regards, Roger Bailey


From: Michael Ossipoff 
Sent: Tuesday, July 28, 2015 4:47 PM
To: Dan Uza 
Cc: sundial list 
Subject: Re: Precision: the measure of all things




(I should clarify again that, for clarity, I like to capitalize _kinds_ of 
whatever sort of thing I'm talking about...such as kinds of sundials or 
hour-systems, though I realize that that capitalization is probably not 
officially correct.)


Another closely-related interesting question is the matter of what _kind_ of 
hours are used. Of course every book or article on sundials points out that, 
before mechanical clocks became widespread, civil time was measured in 
Temporary Hours, which divided the day, from sunrise to sunset, into 12 equal 
parts, and likewise divided the night, from sunset to sunrise, into 12 equal 
parts.


Those books and articles nearly always imply or say that equal hours was a new 
invention when it was adopted--that someone invented a new way to designate 
time, and so it was adopted. Another frequent, and related, statement or 
implication is that the Horizontal Dial was an innovation that was came into 
use upon its invention because, before that, its possibility was there, but 
just hadn't occurred to anyone.


But I read different. I read that Equal Hours were in use by astronomers and 
astrologers long before they were adopted for civil time, and so they were 
hardly a new invention at the time of their adoption for civil time.


In fact, look at a Hemispherium or Hemicyclium. Designed to read in Temporary 
Hours, its hour-line, for a particular hour, crosses a different Equal-Hours 
line, according to the declination. Whether those Temporary Hours were drawn by 
calculation, or by empirical observation, it's plain that it would have been 
obvious to the dial-maker that he was making the 3 p.m. hour-line cross 
different Equal-Hours lines at different solar declinations.


One thing that I'm objecting to is that many of those books imply that 
Temporary Hours are more primitive, and Equal Hours are something more advanced 
that therefore, when invented, immediately replaced Temporary Hours.


Primitive? Rather, a lot more complicated and laborious to make. For sundials, 
and likewise for water-clocks.


People should be impressed by the ingenuity and determination of early makers 
of sundials and water-clocks, who devised Temporary Hours markings and 
mechanisms for them.


As for the Horizontal Dial, of course it's for Equal Hours. That's what it's 
convenient for. Sure, Flat Dials, including Horizontal Dials, and Polar Dials, 
and Equatorial Dials, and others, could have likewise been made for Temporary 
Hours, but they wouldn't have been easier to mark than a Hemicyclium. So it 
isn't surprising if the Horizontal Dial came into use around the same time as 
Equal Hours.


What I read was that, though Equal Hours were well known and used by 
astronomers and astrologers, no one

Re: Precision: the measure of all things

[Roger Bailey]

Hi Dan,

Don't worry, 60 is well represented in time and angular measurements. We have 
60 minutes in an hour, 60 seconds in a minute, 6 x 60 degrees in a circle and 
again 60 minutes in a degree  and sixty seconds in a minute. Why? Being highly 
divisible is only part of the story. Other parts include our year of 365.25 
days, very close to 360 and six equilateral triangles in a circle indicating 
that pi was close to 3 but greater as the arc is longer that the cord. If a 
circle is 360, equilateral triangles are 60 and a quadrant is 90. My preference 
for angular measurement is degrees and decimal minutes as opposed to degrees, 
minutes seconds or decimal degrees, From navigation experience, I recognize a 
minute of latitude is a nautical mile. I can easily handle decimal miles. I 
hate grads using 100 rather that 90 in a quadrant. Some French topo maps still 
use the Paris meridian for longitude and grads for latitudes. This is as 
ridiculous as republican time, 10 hours in a day, 100 minutes in a hour and 100 
minutes in an hour. Get over it as the French did with time. The Babylonians 
were onto something when they defined our base 60 units of measurement.

Regards, 
Roger Bailey 


From: Dan Uza 
Sent: Monday, July 27, 2015 2:59 PM
To: sundial@uni-koeln.de 
Subject: Precision: the measure of all things


Hi everyone,


If you haven't already, you might want to check out the first part of the 
documentary Precision: the measure of all things. It's about the measurement 
of time and length, featuring the topic of sundials. There's an interesting 
theory about how the day got split into 12 hours because this number is highly 
divisible (but why not 60?). I just watched it on Da Vinci Learning.  


Dan Uza
Romania





---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2015.0.6081 / Virus Database: 4392/10318 - Release Date: 07/27/15
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: OS interface new languages

[Roger Bailey]

Thanks Gian for this clarification. By the way I really like your android 
app Sol et Umbra. It provides all the information I really need to 
understand and design sundials. The fact that it designs a sundial for the 
location just by placing it on the surface is amazing.


Thanks again,

Roger Bailey
Walking Shadow Designs

--
From: sun.di...@libero.it
Sent: Friday, July 17, 2015 5:41 AM
To: rtbai...@telus.net; sundial@uni-koeln.de
Subject: OS interface new languages

It seems that my e-mails are bounced to subscribers as void e-mails 
together

with an attachment including my original text.
I don't know why.
Trying again.
This is the text of my original message:

Dear friends,
I'm happy to inform you that Orologi Solari rel. 29.0 now includes a 
Spanish

and French interface.

My gratitude goes to Alejandro Farah (Mexico) and Luigi Ghia (Italy) for
their  invaluable work.

Help files are still to be translated but I hope in the future this can be
fixed.

Would anyone be interested in translating OS to other languages please do 
not

hesitate to contact me.

Greetings.
Gian Casalegno



Messaggio originale
Da: rtbai...@telus.net
Data: 17/07/2015 5.28
A: sun.di...@libero.it, sundial@uni-koeln.de
Ogg: Re:

I don't open letters or attachment with minimal information on the sender
or the contents. How do I know this is safe?

Regards, Roger Bailey

--
From: sun.dials--- via sundial sundial@uni-koeln.de
Sent: Thursday, July 16, 2015 8:11 AM
To: sundial@uni-koeln.de


---
https://lists.uni-koeln.de/mailman/listinfo/sundial














-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2015.0.6081 / Virus Database: 4392/10247 - Release Date: 07/17/15


---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Can I share Universal Analemmatic Sundial image?

[Roger Bailey]

Hello Michael,

The general permitted use allowed in copyright laws is one copy can be made for 
any individual. This allows libraries to function. Posting to a forum requires 
specific permission and attribution. It is better to post a link to the 
original source.

Regards,
Roger Bailey
NASS Secretary


From: Michael Ossipoff 
Sent: Thursday, July 02, 2015 7:40 AM
To: sundial@uni-koeln.de 
Subject: Can I share Universal Analemmatic Sundial image?


I know that often one shouldn’t share an organization’s printed materials. Is 
it alright to send, to individuals, a copy of one of NASS’s PowerPoint files 
with the image of the Universal Analemmatic sun compass? 





Taking the question a step farther, it it alright to post it at a forum 
discussion of methods for solar direction-finding?




That’s an ingenious device, and I was surprised to find out that it was first 
introduced no later than 1660.




The “N” at the noon direction puzzled me at first, until I realized that it was 
the direction of a shadow at noon, not the sun.




That sun-compass is a particularly useful, convenient and versatile one, 
because it can be used even when it isn’t in the sunlight. If you’re in a car 
or train, and shadows of telephone poles are visible outside your window,  then 
the device can give north, by showing the angle between north and a shadow’s 
direction.




Thanks to NASS and to Fred Sawyer for those images of the Universal Analemmatic 
sun-compass.




Michael Ossipoff

26N, 80W








---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2015.0.6037 / Virus Database: 4365/10142 - Release Date: 07/02/15
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Please help identify this architectural sundial and location _ invented by Blasius Gerg!

[Roger Bailey]

Re: Please help identify this architectural sundial and location _ invented by 
Blasius Gerg!Wow, what a complete response to the question on this interesting 
sundial. Thanks Reinhold.

Regards, Roger Bailey


From: Reinhold Kriegler 
Sent: Thursday, June 25, 2015 1:24 PM
To: Sundial Mailing List 
Subject: Re: Please help identify this architectural sundial and location _ 
invented by Blasius Gerg!


Dear sundial friends!

Why don't you look at my ta-dip-link:

http://www.ta-dip.de/sonnenuhren/sonnenuhren-aus-nah-und-fern/b-a-y-e-r-n/oberbayern/die-sonnenuhren-des-blasius-gerg.html
 

and see a bit more of this great Blasius Gerg!

Enjoy!

Reinhold Kriegler



°°

On Thu, Jun 25, 2015 at 10:26 AM -0700, kool...@dickkoolish.com wrote:

https://www.flickr.com/photos/suzanne-gibson/8377866276


 Please help identify this architectural sundial and location recently
 posted on Flickr.

 https://www.flickr.com/photos/schraeglage-urbex/19116095082/in/explore-2015-06-24/



* ** ***  * ** ***
Reinhold R. Kriegler
Lat. 51,8390° N. Long. 12,25512° E. GMT +1 (DST +2)  www.ta-dip.de
http://www.ta-dip.de/dies-und-das/r-e-i-n-h-o-l-d.html 
http://www.ta-dip.de/salon-der-astronomen/musik-im-salon-der-astronomen.html
 Über eine Million Besucher auf  www.ta-dip.de  ! 





---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2015.0.5961 / Virus Database: 4365/10098 - Release Date: 06/25/15
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Does anyone have, or have access to, Compendium vol.12, #1, March 2005?

[Roger Bailey]

Hello Michael,

The referenced article is actually titled Equatorial Projection Sundial 
Projection Vectors by Harold E. Brandmaier. It is about a specific type of 
sundial design, equatorial projection dials like the analemmatic and Foster 
Lambert dials. His technique uses vector and matrix math to solve for this 
specific type of dial with an moving gnomon on any plane, horizontal vertical, 
declining and reclining. It is not directly relevant to the discussion at hand. 
Do you want a copy?

I have Maynall 2nd Edition, not the usually quoted 3rd edition. This discusses 
graphical techniques for reclining declining dials and has formulae in the back 
for specific cases of inclined dials, declining directly north south and 
declining directly east west. Rohr  has six pages of complex math on reclining 
declining dials. I have scanned these and will send you copies.  

Regards, 
Roger Bailey


From: Michael Ossipoff 
Sent: Sunday, April 12, 2015 6:13 AM
To: sundial@uni-koeln.de 
Subject: Does anyone have, or have access to, Compendium vol.12, #1, March 2005?


Alright, I realize that tryng to fix Wikipedia is like trying to bail-out the 
ocean with a thimble. But there's one little matter that I don't intend to let 
pass:

Wikipedia's Sundial article says (regarding Reclining-Declining dials):

In fact it is only in the last decade that agreement has been found on the 
correct hour angle formula for this type of dial [...] Previous formulae given 
by Rohr and Mayall are not correct.

As I mentioned in a previouis post, the Mayall  Mayall formulas that Wikipedia 
quotes, miscopied, in a note to the article, give the correct answers, for 
arbitrarily chosen latitude, recline, decline-angle and time-of-day--right down 
to the last decimal place on the calculator.  ..when a few copying errors and 
variable-misinterpretations are fixed.

Anyway, Wikipedia's big emphasis is on citation of notable sources, especially 
for any implausible or surprising statements (like those quoted above).

The ony citation that's positioned anywhere near the abovequoted passage is to 
Compendium, vol. 12, #1, March 2005.   ...in an article entitled Sundial 
Design Using Matrices.

The person who re-posted that passage after I deleted it won't answer my 
question about whether or not that article is the source of that statement (It 
could just have been intended as a reference for that sentence's mention of the 
use of matrices).

I'd like to get to the bottom of the matter of where Wikipedia got the 
abovequoted statements.

So, could someone take a look at that Compendium article, and tell me if it 
says anything that supports the abovequoted statements--and, if so,what it says?

I'd appreciate it if you'd paste its words on that matter into a post here, or 
an e-mail to me ( at email9648...@gmail.com).

thank you
Michael Ossipoff
~ 26N, 80W





---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2015.0.5863 / Virus Database: 4328/9521 - Release Date: 04/12/15
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Clouding the issue

[Roger Bailey]

Hello Peter and all,

Yes, clouds are a significant, perhaps the overwhelming issue with sundials. 
Night knocks out half the time and clouds at least half of the remaining 
daylight hours. Our BSS colleagues know the problem. The most common sundial 
motto is I count only the sunny hours. This is a truly defeatist attitude in 
these days of technology. Can we do better? The effects of clouds are subtle. A 
slight overcast can destroy the contrast required to read a sundial. Such 
sunlight, not enough to cast shadows can burn pale skin. Fleeting clouds cause 
the shadow to bounce back and forth giving indeterminate time readings 
depending on the side of the sun obscured. I don't think wavelengths are the 
solution. Wavelength effects giving us red sunsets but there seems to be no 
advantage through daytime clouds. But where there is light, there is hope. 
Polarization is detectable through light clouds. Take that old polarizing 
filter from your obsolescent SLR camera or an old pair of Polaroid sunglasses, 
hold towards the sun and turn to see the polarization of the sky. Direct views 
of the sun are not required. Polarized skylight can tell you where the sun is 
when it is obscured. The polarization effect is evident but not distinct. The 
phenomenon exist and is familiar to photographers with polarizing filters, a 
vanishing species. Has the effect been exploited by gnomonists? I don't think 
so. The opportunity remains, a chimera, like analemmatic moondials. I am 
working on the latter for the NASS conference in Victoria BC in June.

Regards, Roger Bailey


From: Peter Mayer 
Sent: Sunday, March 29, 2015 3:13 PM
To: sundial@uni-koeln.de 
Subject: Clouding the issue


Hi,

In the Last Word section of a recent _New Scientist_ Stephen Parish 
raised the question of sundials that might work on cloudy days...Clearly, 
polarisation is possible, but I'm doubtful about shadow casting...

Clouding the issue
  a.. 18 March 2015 
  b.. Magazine issue 3013. Subscribe and save 
  c.. For similar stories, visit the Last Word Topic Guide 
Are there any wavelengths at which the sun still casts a shadow when the sky is 
full of clouds? Could I make a sundial that would work on a cloudy day?

Stephen Parish, London, UK

This article appeared in print under the headline Clouding the issue

 
  a.. From issue 3013 of New Scientist magazine, page 57. 
best wishes,

Peter

-- 
Peter Mayer
Department of Politics  International Studies (POLIS)
School of Social Sciences
http://www.arts.adelaide.edu.au/polis/
The University of Adelaide, AUSTRALIA 5005
Ph : +61 8 8313 5609
Fax : +61 8 8313 3443
e-mail: peter.ma...@adelaide.edu.au
CRICOS Provider Number 00123M
---

This email message is intended only for the addressee(s) and contains 
information that may be confidential and/or copyright. If you are not the 
intended recipient please notify the sender by reply email and immediately 
delete this email. Use, disclosure or reproduction of this email by anyone 
other than the intended recipient(s) is strictly prohibited. No representation 
is made that this email or any attachments are free of viruses. Virus scanning 
is recommended and is the responsibility of the recipient. 



This email has been checked for viruses by Avast antivirus software. 
  www.avast.com 
 







---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2015.0.5856 / Virus Database: 4315/9410 - Release Date: 03/29/15
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Number of sundials

[Roger Bailey]

Hi Art, 

Good question but city is a poor denominator as city sizes ranges from about 20 
thousand to over 10 million. Try sundials per square mile or sundials per 
person. These are more relevant tallies. Here the Queyras in the in France 
Haute Alpes, south of Briancon, scores highest in my experience. Towns there 
still compete on the number and quality of their sundials, with tourist offices 
publishing brochures like 'La Balade de Cadrans Solaires. Here is one example 
that I will be visiting in May 2015.
http://nemausus.com/Balade-des-Cadrans-solaires.pdf Others are like this route 
de cadrans solaire 
http://www.queyras-montagne.com/cadrans-solaires-patrimoine.html There are many 
other examples in Europe: France Italy Austria, Germany. Czech  Republic, etc. 
In France there is an app for the sundial catalogue . See info here. 
http://www.commission-cadrans-solaires.fr/?p=1697 

From: Art Krenzel 
Sent: Tuesday, March 17, 2015 5:21 PM
To: sundial@uni-koeln.de 
Subject: Number of sundials


Here is a good question for such an august group of sundialists (and I don't 
know the real answer).  Which city in the world has the most sundials and how 
many do they have?

Art Krenzel 










  














 








---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2015.0.5751 / Virus Database: 4311/9326 - Release Date: 03/17/15
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Fw: Jack: Duration of sunlight on a particular day

[Roger Bailey]

From: Roger Bailey 
Sent: Wednesday, March 04, 2015 5:28 PM
To: Michael Ossipoff 
Subject: Re: Jack: Duration of sunlight on a particular day


Hello Michael,

I responded to Jack and provided a spreadsheet that calculated sunrise and 
sunset times that included the option for refraction. This spreadsheet also 
included Meeus Algorithms to calculate the equation of time and convert solar 
time to clock time. This spreadsheet was developed to show the sunrise and 
sunset shifts near the winter solstice but the start date is optional. All the 
options are in blue type. The detailed calculations are in a faint type.

I included the spreadsheet in my reply to Jack with a cc. to the list but this 
response was never posted. The spreadsheet is attached to this reply to you and 
anyone on the list who is interested can send me a request. Jack found 
spreadsheet and the chart tab quite useful.

Regards,

Roger Bailey

From: Michael Ossipoff 
Sent: Wednesday, March 04, 2015 6:51 AM
To: sundial@uni-koeln.de 
Subject: Jack: Duration of sunlight on a particular day



Jack: 

You wrote:

I have been trying to figure out how to plot the duration of daylight over  
the course of the year as a function of latitude. (I would generate a  curve 
for each latitude I am interested in.)

[endquote]

You said to disregard physical effects such as atmospheric refraction (and 
solar semi-diameter?). That simplifies the formula.

Where h is the number of equal sundial-hours before or after solar noon at 
sunrise or sunset; dec is declination, and Lat is latitude:

cos h = - tan Lat * tan dec.

Double h, and that's the sunlight duration for that day, the day corresponding 
to some particular value of dec, at some particular latitude Lat.

And yes, _lots_ of people at this list know that. I'm not posting something 
new.  But I just wanted to mention it because I haven't seen it in the answers 
so far.

Michael Ossipoff












---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2015.0.5751 / Virus Database: 4299/9221 - Release Date: 03/03/15


SolsticeRiseSet.xls
Description: MS-Excel spreadsheet
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: sundial village in Italy (near San Marino?)

[Roger Bailey]

Hi Woody,

I would recommend the village of Bellino in the Val Varaita, just over the 
mountains from the French sundial village of St. Veran. Bellino has been on my 
sundial bucket list for some time but every time I have been in the Queyras 
area, the high pass at the border, Col Agnel, has been closed by snow. Bellino 
is also accessible from the Italian side from Cuneo. 

The sundial guide Meridiane di Bellino by Lucio Maria Morra and Fabio Garnero 
is available here.
http://www.sullacrestadellonda.it/meridiane/bellino.htm 

A useful cycle guide is here:
http://italy-cycling-guide.info/piemonte-valle-aosta/piemonte-cycleways-cycle-routes/piemonte-mountain-valleys/piemonte-mountain-valleys-3/

Regards, Roger Bailey

From: Woody Sullivan 
Sent: Friday, February 13, 2015 3:04 AM
To: sund...@rrz.uni-koeln.de 
Subject: sundial village in Italy (near San Marino?)


Greetings, fellow shadow-lovers: 


In the past I have heard mention of a small village in Italy, I think somewhere 
near San Marino, that has many sundials as a sort of theme. Can anyone tell 
me the name of this village and perhaps an associated URL for the sundials?
Many thanks.


Cheers, Woody Sullivan


P.S. I already know about Aiello, near Trieste.




***
Prof. Woodruff T. Sullivan, III   tel  
206-543-7773  
Dept. of Astronomy  Astrobiology ProgramBox 351580
University of Washington
Seattle, WA 98195  USA









---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2015.0.5646 / Virus Database: 4284/9108 - Release Date: 02/13/15
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: A question for the mathematically inclined

[Roger Bailey]

Hi Jack,

Let me offer the solution to a related question that came up while hiking 
with friends around the time of the solstice. One friend asked
about the changes he had noticed in the times of sunrise and sunset near 
the solstice. Sunrise kept getting later after the solstice but sunset 
minimum was before the solstice. Why?


I responded saying it was due to the difference between clock time and 
solar time. This difference, called the Equation of Time, is due to the tilt 
of the earth's axis and the eccentricity of the earth's orbit. As an 
engineer I follow the dictum Don't speculate! Calculate. To fully answer 
the question, I developed a spreadsheet to calculate sunrise and sunset 
times for specified dates at a specified location, Sidney at 48.66 N, 123.4 
W and specified atmospheric refraction (50 arc min). The spreadsheet with 
all the details, chart and data tabs is attached. Anything in the tables in 
blue type, like location, refraction and start date you can change to see 
the effect. Anything in ghost letters is part of the internal calculations 
for solar declination and the equation of time using Meeus Astronomical 
Algorithms as well as sunrise and sunset times by spherical trigonometry.


Jack, the math is all there for to answer your question. Just change the 
data in cells with blue printing. I calculated but did not plot the 
duration. It is easy to do. These calculations covered a two month period 
around the winter solstice but changing the start date changes the whole 
period of interest. It is easy to change the increment from 1 to any other 
increment like 7 for each week and copy this down through the date column. 
Copy the last full row to extend the calculation to a full year. It is all 
there for you to hack to answer the question on the effect of latitude.


Regards,
Roger Bailey
Walking Shadow Designs

--
From: Jack Aubert j...@chezaubert.net
Sent: Tuesday, February 03, 2015 12:23 PM
To: 'Sundial List' sundial@uni-koeln.de
Subject: RE: A question for the mathematically inclined

OK, I would also like to take a turn and ask a question to the 
mathematically inclined:


I have been trying to figure out how to plot the duration of daylight over 
the course of the year as a function of latitude.  (I would generate a 
curve for each latitude I am interested in.)


I believe the result should be a sine curve which looks comparatively flat 
at the equator, growing increasingly steeper until the polar circle, where 
it would turn into a binary step curve and the six month day turns to six 
month night -- leaving aside physical effects like refraction.  I am 
particularly interested in the slope of the curve around the equinoxes at 
northern latitudes, when the transition from long summer days to short 
winter days is quite abrupt.


Jack Aubert


SolsticeRiseSet.xls
Description: MS-Excel spreadsheet
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: A question for the mathematically inclined

[Roger Bailey]

Hello John,

I  routinely use Napier's Analogue as suggested by Fred Sawyer when I asked 
this question several years ago. This involves an intermediate step 
involving an angle B. Here are the formulae.


Napier's Analogues: Knowing Latitude, Declination and Azimuth, Solve for 
Altitude and TimeFindangle B : Sin B =Sin Az Cos Lat/ Cos Dec.

Then Tan .5(90-Alt)=Tan .5(Lat-Dec)Cos.5(B-Az)/Cos .5(B+Az),
Then the Sine Rule for t: Sin Az=CosDec Sint/CosAlt or 
Sint=SinAzCosAlt/CosDec


These are fairly easy to program into a spreadsheet.

Regards, Roger Bailey



--
From: John Goodman johngood...@mac.com
Sent: Saturday, January 31, 2015 7:05 AM
To: Sundial List sundial@uni-koeln.de
Subject: A question for the mathematically inclined


Dear dialists,

Does anyone know a formula for calculating the hour angle given the 
azimuth, declination, and latitude?


I’d like to know the time of day, throughout the year, when the sun will 
be positioned at a particular angle. This will allow me to determine when 
sunshine will stream squarely through a window on any (sunny) day.


I’ve seen several formulae for calculating azimuth. I suspect that one of 
them could be rewritten to solve for the hour angle given the azimuth 
instead of the finding the azimuth using the hour angle (plus the 
declination and latitude). Unfortunately, I don’t have the math skills for 
this conversion.


Thanks for any suggestions.
---
https://lists.uni-koeln.de/mailman/listinfo/sundial



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2015.0.5646 / Virus Database: 4273/9032 - Release Date: 01/31/15


---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Sundials in Transylvania need your help!

[Roger Bailey]

Hello Dan,

What an excellent project! I have made a minor contribution to show support. 

Like most people these days, I am wary about internet security and privacy. 
Most of us are reluctant to provide personal information and credit card 
information. I did so using PayPal, a known and trusted method of transferring 
funds anonymously. 

Best wishes on the success of your project.

Roger Bailey  


From: cerculdestele . 
Sent: Friday, August 15, 2014 2:55 AM
To: sundial@uni-koeln.de 
Subject: Sundials in Transylvania need your help!


Dear Group, 


Please have a look at my Indiegogo campaign.
It's about publishing a book dealing mainly with sundials in Transylvania. The 
manuscript is almost ready for printing. It will be the first photographic 
inventory/catalog of sundials in Romania (Eastern Europe).


The link is: http://igg.me/at/sundials



You can help by sharing the link and funding the project.



Many thanks!


Dan





---
https://lists.uni-koeln.de/mailman/listinfo/sundial

---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Tour de Sundials

[Roger Bailey]

Thanks Frank. I will correct the waymarks based on your comments.

Enjoy the Tour de France. They also have a stage in the heart of the Zarbula 
zone, day 14 Grenoble to Risoul. I checked my map showing all the remaining 
Zarbula Sundials and could not identify any that are on the specific tour de 
France route. See www.tinyurl.com/ZarbulaSundials


Regards, Roger Bailey


--
From: Frank King frank.k...@cl.cam.ac.uk
Sent: Monday, July 07, 2014 2:14 AM
To: Roger Bailey rtbai...@telus.net
Cc: sundial@uni-koeln.de
Subject: Re: Tour de Sundials


Dear Roger,

I much enjoyed your message and
Reinhold's comment, also your
tiny URL at:

  http://tinyurl.com/CamSunTour

The S. Botolph's dials have been
much improved recently by regilding
but I don't have a fresh picture.

You have a good photograph of what
you describe as:

 Polygon Sundial,
 Downing Quadrangle,
 Cambridge, UK

I wonder whether you could tweak
this a little...

1. A polygon is a plane figure.
   This is a POLYHEDRAL sundial,
   being three dimensional.

   [If you like you can say it is an
elongated square gyro bicupola!]

2. There are absolutely NO
   quadrangles in Cambridge,
   not one.  They do have them
   in Oxford.

   Here such a thing is called a
   court.  Sadly, you can't just
   change the word because that
   would be talking about Downing
   College.  To reach the polyhedral
   sundial...

 Enter the Downing Site off
 Downing St though the gateway
 under the arch.

Alas, this isn't the dial I was
referring to.  The one the Tour de
France cyclists might glimpse is
at Downing College.  You can see
it at the bottom of page two of:

 http://www.cl.cam.ac.uk/~fhk1/Sundials/WriteUps/CBsundialWalk.pdf

At this moment I am almost in
Lockdown.  I can't cross the
roads easily and there are
helicopters making a dreadful
racket right outside my window.

It IS sunny and the few dials
I have checked are looking fine!

Frank



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4716 / Virus Database: 3986/7812 - Release Date: 07/07/14




-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4716 / Virus Database: 3986/7812 - Release Date: 07/07/14

---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Tour de Sundials

[Roger Bailey]

Thanks Frank,

I waymarked some of these dials following the 2007 BSS meeting in Cambridge. 
This tiny url will take you to waymarking.com for pictures and details. 
http://tinyurl.com/CamSunTour


Regards, Roger Bailey

--
From: Frank King frank.k...@cl.cam.ac.uk
Sent: Saturday, July 05, 2014 10:15 AM
To: sundial@uni-koeln.de
Subject: Tour de Sundials


Dear All,

In less than 48 hours, Stage 3 of the
Tour de France will start about 500m
from where I am sitting now.  The noise
is deafening already!

I pondered how many Cambridge sundials
the competitors might be able to see
in the first mile or so...

1. With agile necks they might see
   into the gate of Downing College
   where there is a modern horizontal
   dial.

2. The next prospect is Christ's
   College where there is a good
   wall dial visible through the
   great gate.

3. They then pass Sidney Sussex
   College where there is a
   splendid armillary sphere but,
   alas, just on the other side
   of a high wall.

4. They should be able to glance
   right and see two or three of
   the six dials on the Gate of
   Honour at Caius College.

5. They go past King's College
   but they won't see either of
   the dials there and they get
   close to Queens' College but
   won't see the famous dial
   there.

6. They should see the recently
   restored double dial on
   S. Botolph's Church which
   veritably gleams when the
   sun shines on the gold leaf.

7. They then pass Pembroke College
   but won't see my dial there
   alas.  I wasn't consulted about
   the tour route!

The best bet for a photograph of the
peloton racing past a sundial is
S. Botolph's but, sadly, I shall not
be there.  I am ringing church bells
at that instant to mark the event.

Maybe one of the French readers of
this list can find a sundial on the
race route which permits a photograph
of both peloton and dial!

There must be some good candidate dials
in some of the French villages.

Frank King
Cambridge, U.K.

---
https://lists.uni-koeln.de/mailman/listinfo/sundial



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4716 / Virus Database: 3986/7803 - Release Date: 07/05/14




-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4716 / Virus Database: 3986/7803 - Release Date: 07/05/14

---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: sundials in schools

[Roger Bailey]

Hello Linda and all,
Yes, this is all it takes, the combination of an analemmatic dial and a 
horizontal dial provide a quick determination of true north and true (solar) 
time. Many old pocket dials, the size of today's smart phones, provided this 
information. What goes around comes around. People still need to no the time 
and direction, so easily provided by the analemmatic horizontal dial 
combination in a simple flip dial.


Regards, Roger Bailey

--
From: Linda Reid linda.r...@fastmessage.co.uk
Sent: Friday, July 04, 2014 6:06 PM
To: sundial@uni-koeln.de
Subject: Re: sundials in schools

In message 
6fdf1b3f189fbd5c34dc9ac34702c0da.squir...@webmail.dickkoolish.com

 kool...@dickkoolish.com wrote:


There are astronomy programs like Stellarium and
smartphone apps that give the azimuth of the sun
at a given time. That and a protractor will give
you true north.




An EASY way, will be to use a 'combined' Horizontal AND Analemmatic dial.

You just rotate this, until it shows the SAME time on BOTH dials - which
then means that it is AUTOMATICALLY aligned in the North/South direction.


No need for any computer 'Apps' - although you would need some sunshine!


Hope this is of some help - Linda Reid.





 I would also love to see sundials in schools. Not just an analemmatic
 dials
 but the multi dial as well.

 This is why I am trying to find an easy way to find north.

  I would like to be able to use a horizontal dial and rotate it until 
 it
 reads the true time. Obviously this won't work with a standard 
 horizontal
 dial because we are not all on the same longitude. The other reason is 
 the

 equation of time.

  However, I believe it would work if there was a website that calculate
 setting your watch to LAT instead of LMT. This website would have to 
 take

 in account the longitude as well as the day of the year it is. You then
 rotate the sundial until it is the correct time on your watch.



 Cheers
 Donald Christensen
 0423 102 090
 www.sundialsforlearning.com




--

---
https://lists.uni-koeln.de/mailman/listinfo/sundial



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4716 / Virus Database: 3986/7800 - Release Date: 07/04/14




-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4716 / Virus Database: 3986/7800 - Release Date: 07/04/14

---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Lunar Analemma

[Roger Bailey]

Hi David and all,

There are lunastices generally called lunar standstills. These occur every 
month as opposed to every year for solstices. As the moons orbit is tilted 
about 5° from the ecliptic, these lunastices are different from the solstices 
and vary over an 18 year period from major to minor and back to major 
standstill due to precession. Stonehenge and other ancient megaliths are 
reported to be demonstrations of lunastices. The motions of the moon are very 
interesting as such a short cycle, a month, and only 18 years in their 
precession cycle. This opens up the topic of moon dials, specifically 
declination dependant moon dials. Stay tuned as this lunacy unfolds at the NASS 
conference this year.

Regards, Roger Bailey


From: David Bell
Sent: Friday, May 30, 2014 12:12 PM
To: Robert Terwilliger
Cc: sundial@uni-koeln.de
Subject: Re: Lunar Analemma


Great analemma (Lanalemma?) photo!


So, how does it continue, month by month? In a spiral fashion, then return over 
the same area of the sky, after slowing to a halt? Are there lunastices, 
then? If so, how do they correspond to the solstices!


Dave

Sent from my iPhone

On May 30, 2014, at 2:34 AM, Robert Terwilliger b...@twigsdigs.com wrote:


  Earth Science Picture of the Day

  http://epod.usra.edu/blog/2014/05/lunar-analemma.html



  As part of my morning routine I take a look at a page I made with two 
“Pictures of the Day” Astronomy and Earth Science. I made up another one so 
anyone interested can take a look at them. Bookmark it.



  http://www.twigsdigs.com/annex/picture/picture_od.html



  It uses Iframes so scrolling takes some getting used to.



  Bob

  ---
  https://lists.uni-koeln.de/mailman/listinfo/sundial







---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4592 / Virus Database: 3950/7577 - Release Date: 05/28/14



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4592 / Virus Database: 3955/7594 - Release Date: 05/30/14
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Moon dial.

[Roger Bailey]

Hello David,

Girolamo Fantoni published Moondials in the BSS Bulletin 92-1. He describes a 
new design based on ideas by Ozanam (1699) using 15 lines for the lunar phases 
each day of the month. Rafael Soler has incorporated moondials using this 15 
line technique as well as correction charts technique on some of his 
multifaceted sundials dials in Mallorca. The best example is the 1 m cube in 
the Soller Botanical Garden. Here are links to a couple of pictures.
https://picasaweb.google.com/lh/photo/ewOmDBn4RiFiCJDsANAtLSVg4eN4RQqVmec5g1exKas?feat=directlink
https://picasaweb.google.com/lh/photo/FLHiObHT9gJ7b0wbTU4K5yVg4eN4RQqVmec5g1exKas?feat=directlink

His book Diseno Y Construccion de Relojes de Solar y de Luna describes the 
techniques on pages 405 to 413. How is your Spanish?

At the NASS conference in 2012 I gave a presentation on Sundials in Mallorca 
showing many examples of Rafael's remarkable designs. The cube dial is 
described on slides 52 to 56. I have uploaded in to a personal website. This 
link will start the download of the 28 MB PowerPoint file.
http://www3.telus.net/public/rtbailey/BSS%20Tours/Sundials%20in%20Mallorca.ppt

Enjoy,
Roger Bailey
Walking Shadow Designs

ps. I am currently working on the concept of an analemmatic moondial. This 
Lunacy will be presented at the NASS conference this August.

  --
From: David da...@davidbrownsundials.com
Sent: Tuesday, May 13, 2014 11:29 PM
To: Sundial list sundial@uni-koeln.de
Subject: Moon dial.

 Dear All,
 I have had a request to construct a moon dial for a vertical east-facing 
 wall.
 This is new territory for me.
 Can anyone point me in the direction of sources/computer programmes that 
 would give me guidance?
 David Brown
 Somerton, Somerset, UK
 ---
 https://lists.uni-koeln.de/mailman/listinfo/sundial



 -
 No virus found in this message.
 Checked by AVG - www.avg.com
 Version: 2014.0.4577 / Virus Database: 3950/7493 - Release Date: 05/14/14



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4577 / Virus Database: 3950/7493 - Release Date: 05/14/14
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Calculating the Equation of Time and other Solar Parameters

[Roger Bailey]

Thanks Kevin,

A quick review demonstrated how useful your work can be for folk like us. Here 
is a specific example. I have been working with solar and lunar ephemerides 
date from the JPL Horizons website. http://ssd.jpl.nasa.gov/horizons.cgi#top 
This site provides a wealth of data that the user can customize for their own 
purposes. The problem is the user does not know how the data was calculated nor 
how it is to be used  The Explanatory Supplement helps but it is difficult to 
understand.  One simple example is understanding a solar data compilation that 
provided among other things Right Ascension and Declination. But I really 
wanted the EQT. Your formula 9 in Part 1 gave me the simple relationship, 
obvious in hindsight that I was looking for, the conversion of RA to EQT.

I look forward making good use of your work. Thank you for making it available.

Thanks again,
Roger Bailey
Walking Shadow Designs




From: Kevin Karney
Sent: Sunday, February 23, 2014 11:32 AM
To: sundial@uni-koeln.de List
Subject: Calculating the Equation of Time and other Solar Parameters


Dear Friends


I have spend many happy hours during this wet, wet winter investigating and 
learning how to calculate all the solar parameters that a gnomonist might 
possibly need  - Equation of Time, Declination, RA, Altitude, Azimuth, Time of 
Sunset/Rise, etc, etc.


I have been surprised to find that - with traditional calculation methods and 
an absolute minimum of astronomical information -  it is possible to calculate 
everything from first principles to a surprising degree of accuracy.


Other than location and local time, only six pieces of astronomical information 
are required - obliquity, eccentricity, Sun’s GHA at 1/1/2000, longitude of 
perihelion, a single precessional constant and the length of the tropical year. 
Accuracies for the EOT are +/- 2 seconds of time For altitudes/azimuths, less 
than 1 minute of arc - much better than needed by most gnomonic problems.


If any of you are interested in such calculations, I have loaded a document 
with all the astronomical theory and background plus the code onto my website
www.precisedirections.co.uk/sundials
The code is written in Python, a language available on every type of computer, 
which is very easily understood, quite easily learnt and very easily translated 
into any other coding language you might like.


If you own an iPad or iPhone, and are prepared to buy a cheap little app called 
Pythonista, the code will extract locational  time information from your phone 
- so you do not even have to input this to get your calculations done


You might also like to see a graphic of a civil mean time horizontal dial, 
which I think is called a hectomoros dial,  that is destined for my garden. 
This is also on the website.


Enjoy
Kevin





---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4335 / Virus Database: 3705/7118 - Release Date: 02/23/14



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4335 / Virus Database: 3705/7118 - Release Date: 02/23/14
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Garden planning problem

[Roger Bailey]

Hi Dave,

My initial recollection was of a cosine effect. So I drew a little sketch to 
clarify the situation. I specified the angle as the elevation, the altitude 
measured from the horizontal. It would be the cosine for the angle measured 
from the zenith. The area of the direct projection is Pi R squared. The area 
of the ellipse on the projected on the ground is Pi R times the semi-major 
axis. This is R/ Sin Alt so the area is Pi R squared/Sin Alt. I considered 
the illumination inversely proportional to the area so directly related to 
the sine of the elevation, the altitude angle.  QED. or is my logic wrong?


At sunrise the elevation is zero, sine =0, the intensity is zero. Directly 
above the elevation is 90° and Sine 90 = 1. The intensity is full, 
undiminished by spreading over a larger area. Radiation from the sun follows 
the inverse square law. Twice the distance from the sun gets 1/4 the 
intensity but that is not the effect being discussed in this gray posting.


Regards, Roger

--
From: David Bell db...@thebells.net
Sent: Friday, January 03, 2014 2:06 PM
To: Roger Bailey rtbai...@telus.net
Cc: Marcelo mmanil...@gmail.com; Sundial List sundial@uni-koeln.de
Subject: Re: Garden planning problem


One thought on that gray posting, Roger:
I may remember incorrectly, but I thought illuminance on a surface was 
proportional to the square of the cosine of the incidence angle.


Dave

Sent from my iPhone

On Jan 2, 2014, at 8:07 PM, Roger Bailey rtbai...@telus.net wrote:


Hello Marcelo,

Many on this list empathize with your problem. We know what we want to do 
but the math is unfamiliar. In reality the trigonometry here is very 
simple, as you have laid out the problem.  The ratio of the height of the 
shadow caster, G to the shadow length, L is the Tangent of the altitude, 
H.  Tan H = G/L. Or rearranging  L = G/Tan H. The shadow length is equal 
to the height of the shadow caster divided by a simple number. the 
Tangent of the solar altitude angle H.


This assumes you know the altitude angle. At solar noon when the sun is 
on the meridian, this is an easy calculation as  the Noon altitude equals 
the co-latitude minus the solar declination  or  H = 90-Lat-Dec.


This assumes you know your latitude and solar declination. Latitude is 
easy from maps, websites, GPS etc. Solar declination is not as quite as 
easy but many tables, almanacs, programs and websites can give it to you. 
Google solar declination.


What if it is not noon? The altitude and azimuth are still relatively 
easy to calculate using the classical formulae of spherical trigonometry 
used by navigators with sextants. Sin Sin Sin Cos Cos Cos is the first 
equation to know. Sin H = Sin Dec x Sin Lat + Cos Dec x Cos Lat x Cos t. 
Input your latitude, declination and time as an angle from noon to 
calculate H, the altitude angle that determines the shadow length.  These 
intimidating trig expressions are just numbers, simple numbers that you 
can add, subtract, multiply and divide.


But have you considered the Sine effect of the incident light? Light 
straight down on a surface such as a flowers leaves is fully effective. 
As the angle tilts from straight down to a lower angle, the effective 
incident light is diminishes. How  much? By the Sine  of the altitude. 
Straight on the altitude is 90° and Sin 90° = 1. At altitude = 45°,  Sin 
45 = 0.707, so the light is 70% as intense. At 30° altitude, the 
intensity is halved as Sin 30 = 0.5.


Many on this mailing list have found the a little geometry, trigonometry 
and even spherical tri can be very useful in solving problems like yours.


Regards, Roger Bailey
--
From: Marcelo mmanil...@gmail.com
Sent: Thursday, January 02, 2014 11:37 AM
To: Sundial List sundial@uni-koeln.de
Subject: Garden planning problem


Hello fellow dialists, how are you?
I'm with a problem here which doesn't concern exactly to sundials, but
since it deals with sun's position and his shadows, I couldn't think
of anyone better than you to help me.
I have a little garden here at home, a walled area where I grow some
plants in pots. I've found that, depending on the place, teher's a
difference greater than 2.5 hours in the sunlight a plant receives,
and that affects greatly its development.
I've measured the shadows cast before and after true noon during
summer solstice (I live slightly south to the Tropic of Capricorn). I
could repeat the process during equinox and winter solstice, but
that's a boring task, and above all, if the weather is cloudy I'll
miss the chance.
So, can you tell me some trigonometrical method for calculating the
shadows, using sun's altitude and azimuth? I couldn't devise one by
myself.
Thanks in advance, and Happy New Year!

Marcial
---
https://lists.uni-koeln.de/mailman/listinfo/sundial



-
No virus found in this message.
Checked by AVG

Re: Garden planning problem

[Roger Bailey]

Hello Marcelo,

Many on this list empathize with your problem. We know what we want to do 
but the math is unfamiliar. In reality the trigonometry here is very simple, 
as you have laid out the problem.  The ratio of the height of the shadow 
caster, G to the shadow length, L is the Tangent of the altitude, H.  Tan H 
= G/L. Or rearranging  L = G/Tan H. The shadow length is equal to the height 
of the shadow caster divided by a simple number. the Tangent of the solar 
altitude angle H.


This assumes you know the altitude angle. At solar noon when the sun is on 
the meridian, this is an easy calculation as  the Noon altitude equals the 
co-latitude minus the solar declination  or  H = 90-Lat-Dec.


This assumes you know your latitude and solar declination. Latitude is easy 
from maps, websites, GPS etc. Solar declination is not as quite as easy but 
many tables, almanacs, programs and websites can give it to you.  Google 
solar declination.


What if it is not noon? The altitude and azimuth are still relatively easy 
to calculate using the classical formulae of spherical trigonometry used by 
navigators with sextants. Sin Sin Sin Cos Cos Cos is the first equation to 
know. Sin H = Sin Dec x Sin Lat + Cos Dec x Cos Lat x Cos t.  Input your 
latitude, declination and time as an angle from noon to calculate H, the 
altitude angle that determines the shadow length.  These intimidating trig 
expressions are just numbers, simple numbers that you can add, subtract, 
multiply and divide.


But have you considered the Sine effect of the incident light? Light 
straight down on a surface such as a flowers leaves is fully effective. As 
the angle tilts from straight down to a lower angle, the effective incident 
light is diminishes. How  much? By the Sine  of the altitude.  Straight on 
the altitude is 90° and Sin 90° = 1. At altitude = 45°,  Sin 45 = 0.707, so 
the light is 70% as intense. At 30° altitude, the intensity is halved as Sin 
30 = 0.5.


Many on this mailing list have found the a little geometry, trigonometry and 
even spherical tri can be very useful in solving problems like yours.


Regards, Roger Bailey
--
From: Marcelo mmanil...@gmail.com
Sent: Thursday, January 02, 2014 11:37 AM
To: Sundial List sundial@uni-koeln.de
Subject: Garden planning problem


Hello fellow dialists, how are you?
I'm with a problem here which doesn't concern exactly to sundials, but
since it deals with sun's position and his shadows, I couldn't think
of anyone better than you to help me.
I have a little garden here at home, a walled area where I grow some
plants in pots. I've found that, depending on the place, teher's a
difference greater than 2.5 hours in the sunlight a plant receives,
and that affects greatly its development.
I've measured the shadows cast before and after true noon during
summer solstice (I live slightly south to the Tropic of Capricorn). I
could repeat the process during equinox and winter solstice, but
that's a boring task, and above all, if the weather is cloudy I'll
miss the chance.
So, can you tell me some trigonometrical method for calculating the
shadows, using sun's altitude and azimuth? I couldn't devise one by
myself.
Thanks in advance, and Happy New Year!

Marcial
---
https://lists.uni-koeln.de/mailman/listinfo/sundial



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4259 / Virus Database: 3658/6969 - Release Date: 01/02/14




-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4259 / Virus Database: 3658/6971 - Release Date: 01/02/14

---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Information wanted, on 'badly designed' public sundials

[Roger Bailey]

Hello Reena,

I would not call this a badly designed public sundial. The gnomonic design 
looks like a standard Sunclocks layout showing time corrected for 
longitude and daylight savings. Note the two hour ellipses, the larger one 
for standard time corresponding with the expanded date table and longer 
shadows for the fall and winter months. Note the noon offset from the 
meridian for the longitude correction.


Raised hour markers and date table are very common  with analemmatic 
sundials. They provide a third dimension to add sculpture presence. Flat two 
dimensional markings are boring. The raised surfaces give the user something 
to see and interact with. Observe people using the dial, especially 
children, the more free range the better. They will hop along the hour 
markers as stepping stones, inventing interactive games as they play on the 
structure.  Of course it is not vehicle or pedestrian friendly. Kids should 
not play on the streets and other vehicle friendly areas. Kids should play 
in areas like this public sundial that challenge their minds and bodies.


Hi Brian,
In response to your note on risk taking Canadians, yesterday we hiked 
through the forest along the edge and cliffs of the Cowichan River on 
Vancouver Island observing the Chinook salmon run, large 20 kg lusty fish 
swimming upstream through the rapids and up the waterfalls to complete their 
life cycle. We were well aware of bears attracted to the river to feed on 
the salmon, as we observed many fresh remains of fish and steaming bear scat 
along the trail. We actually saw no bears on this trip as we skipped along 
like free range kids even though the average age of the group members was 
72.


Regards,
Roger Bailey



--
From: Reena Gagneja reenagagne...@gmail.com
Sent: Thursday, October 24, 2013 7:46 AM
To: sundial@uni-koeln.de
Subject: Information wanted, on 'badly designed' public sundials



Dear List Members (especially in UK),

I am intending to compile a list of sundials, in public places - which
people do NOT like, either because it is inaccurate or badly designed.


Does anyone have further information on this 'Analemmatic' layout, at
Colne (see attached photograph) - in terms of the Client, or Designer?

I have managed to establish that the component-parts were supplied by
a company (in Yorkshire), named Fosstone - but I would like to know
who 'commissioned' it, or designed the layout of the stone pieces.


All I have been able to find on the internet are basically negative
comments about it - being a waste of public money, an obstruction,
danger to pedestrians, etc.  Why would anyone create such a feature
which is not 'vehicle-friendly', and potentially dangerous if people
were to trip on it?  Why not simply set all its parts 'flush' with
the ground-level, instead of having that central section raised up?

Apart from anything else, the cost would have been much reduced.


With my thanks, in advance - for any further information, on this.


Sincerely,

Reena Gagneja.


--







---
https://lists.uni-koeln.de/mailman/listinfo/sundial







-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4158 / Virus Database: 3614/6776 - Release Date: 10/23/13 




-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4158 / Virus Database: 3615/6779 - Release Date: 10/24/13

---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Klementinum's sundials and armillary sphere

[Roger Bailey]

Hello Alexey,

I visited the Klementinum in 2006 and was very impressed with the sundials, 
specifically the painted wall sundials in the three courtyards and the sundials 
on and in the Observatory tower. I learned a lot form these remarkable sundials 
installed by the Jesuits during the counter-reformation. These sundials are 
featured in my presentation Timelines given to NASS, BSS and RASC audiences. 
It is available on my website www.walkingshadow.info Click on Walking Shadow 
(Sundials) and Presentation #8 Timelines. Public access to the Student's 
Court and Economics Court were easy, but access to the Vine Court via the 
National Library was difficult. Finally the security guard let me in to take a 
few pictures. Restoration work was underway on a couple of the sundials in the 
Economics Court

I took the tour of the Observatory Tower to see the special meridian used to 
set Prague time. My waymark is posted here; 
http://www.waymarking.com/waymarks/WM86NC_Meridian_Sundial_in_the_Clementunum_Astronomical_Tower_Prague


The armillary on top of the tower is evident in my pictures so it seems to be a 
permanent fixture. I don't recall seeing an exhibition of portable dials.

Regards,
Roger Bailey


From: Алексей Крутяков
Sent: Tuesday, October 22, 2013 2:26 PM
To: sundial
Subject: Klementinum's sundials and armillary sphere


Dear dialists,

Being in Prague last week, I went to Klementinum in order to take pictures of 
portable sundials that should be presented there.
As I failed to get inside because of some reconstruction works, I've made 
photos of very nice vertical east sundials and armillary sphere on the top of 
Klementinum.

http://www.analemma.ru/images/history/Klementinum_East_View.jpg
http://www.analemma.ru/images/history/Klementinum_South-East_View.jpg
http://www.analemma.ru/images/history/Klementinum_South_View.jpg

As one can see from the photos (on south view armillary sphere is in original 
resolution), orientation of the sphere does not correspond to east wall dials, 
which showed the true time perfectly well (it was about 12:35, e.g. near true 
noon).

May be somebody knows something about Klementium reconstruction. I also hope 
very much, that it is a temporary position of the sphere, but not mistake.
I'll be gratefull for any information about exsibition of portable dials inside 
Klementium, if any exists.

Thank you.

Regards,

Alexey Krutiakov

56 06N
37 54E





---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4158 / Virus Database: - Release Date: 10/21/13



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4158 / Virus Database: 3614/6773 - Release Date: 10/22/13
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: a unique sundial on a cylindrical column of opal glass

[Roger Bailey]

The article Un cadran solaire insolite sur colonne dans l'ancien couvent de 
la Baumette by Manuel Pizarro Gavilán was published in Le Gnomoniste in Dec 
2010 and is available here: 
http://cadrans-solaires.scg.ulaval.ca/v08-08-04/quidnovi/XVII-4-p12-20.pdf


This excellent article was also published in the SAF 'Cadrans Info in 
October 2010. Dials like these are often called top hat or filter sundials 
in English and filterhut in Austrian.


Regards, Roger Bailey

--
From: Helmut Sonderegger (Tele2) h.sondereg...@utanet.at
Sent: Sunday, October 20, 2013 1:19 AM
To: f.w.m...@rug.nl
Cc: sundial@uni-koeln.de
Subject: Re: a unique sundial on a cylindrical column of opal glass


Dear Frans,
here a photo of such a Filterhut dial with vertical slits around the
edge. This sundial was found some years ago by Manuel Pizarro Gavilan
on a column in the couvent of La Baumette near Angers (France). Time is
read where the shadow of such a single stick is shortest i.e. vertically
down.

On Valentin Hristov's website you find constructions where this edge
outside the cylinder is turned inside (with concetric hole in the circle
plane on the top of the cylinder):
http://www.mysundial.ca/tsp/deltacad_sundial_macros_vh_cylinder2.html.
And in these versions finally one can get  Willy Lender's beautiful 
sundial.


Best wishes
Helmut

Am 16.10.2013 21:09, schrieb Frans W. Maes:

Dear Helmut  all,

You are right, Willy Sullivan's sundial is not a shepherd dial. It is
very similar to a so-called Filterhut dial; I am sure you know the
type. For those who don't: that's understandable, as only a handful of
examples exist. Attached is a picture of a specimen at the abbey of
St. Martin-de-Boscherville (near Rouen in northern France). The time
is read at the highest point of the ring's shadow edge.

According to René Rohr, this type was described already by Athanasius
Kircher in the 17th century. The accuracy is sometines increased by
vertical slits around the edge, which makes it easier to find the
sun's azimuth. Rohr continues to tell that the Arab scientist Abul
Hassan al Marrakushi described already in 1272 a version in which only
a small radial strip of the ring was present. Which exactly matches
Sullivan's dial!

Best regards,
Frans Maes









---
https://lists.uni-koeln.de/mailman/listinfo/sundial







-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4158 / Virus Database: 3614/6765 - Release Date: 10/19/13 




-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4158 / Virus Database: 3614/6765 - Release Date: 10/19/13

---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Tony Moss - hacked

[Roger Bailey]

Hi Tony,

James Fallows wrote an excellent article on his experience when his wife's 
gmail was hacked. Here is a link. 
http://www.theatlantic.com/magazine/archive/2011/11/hacked/308673/  Even with 
his top level connections with Google and the tech community, the recovery was 
difficult. Google changed some of their practices due to this exposure but the 
recovery process is still difficult.

Good Luck, Roger Bailey


From: Tony Moss 
Sent: Friday, September 27, 2013 10:43 AM
To: sundial@uni-koeln.de 
Subject: Re: Tony Moss - hacked


Hi all,
 A thousand apologies to anyone who has had trouble with this nasty 
event.  My email password is now reset and more secure. At least Gmail support 
could tell me how to restore my vanished email address list successfully  Phew! 
 

Whoever did this (I think) also wiped all my 'Sent Mail' and 'in Box' ith some 
important files so I'm hoping that Gmail have a means of restoring them too, 
although any suggestions are very welcome.

Thanks to David Brown for making this announcement.

Best,

Tony M.







-Original Message-
From: rmallett postmas...@rmallett.plus.com
To: David da...@davidbrownsundials.com
CC: sundial@uni-koeln.de
Sent: Fri, 27 Sep 2013 18:18
Subject: Re: Tony Moss - hacked


On 27/09/2013 11:50, David wrote: 
 Dear All, 
 Please note that Tony Moss has had his computer hacked and cannot  
 communicate for the time being. He has asked me to let the sundial  list 
 know of his predicament. 
 David Brown 
 Somerton, Somerset, UK 
 --- 
 https://lists.uni-koeln.de/mailman/listinfo/sundial 
 
 
 
That's what you get for using something like Gmail :-) 
 
-- -- 
Richard Mallett 
Eaton Bray, Dunstable 
South Beds. UK 
 
--- 
https://lists.uni-koeln.de/mailman/listinfo/sundial 
 






---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4142 / Virus Database: 3604/6702 - Release Date: 09/26/13
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Visibly Moving Gnomon Shadows

[Roger Bailey]

I am reminded of Galileo's supposed recant, the mutter translated as and yet 
it moves. Yes it does and it can be observed in specific circumstances.

When we setting the Ottoman sundial in St Louis I sensed I could see the shadow 
move as we tracked the shadow against the scale. At the NASS conference in 
Tucson we observed with John Carmichael the rapid movement of the shadow using 
shadow sharpeners determining the timelines under the McMath Solar Observatory. 
Here we could clearly see the shadow move. A huge sundial gnomon and favourable 
geometry accelerated the motion.

I expect observers of the Sun in the Church phenomenon on meridians in 
various churches in Europe can see the sun spot move. Math? Phaff. Believe what 
you see.

Regards, Roger Bailey

ps. The word for the day, pfaff is a slang term for wasting time, doing 
nothing very productive.


From: Dave Bell
Sent: Wednesday, August 07, 2013 6:47 AM
To: 'Kevin Nute' ; 'SundialMailingList'
Subject: RE: Visibly Moving Gnomon Shadows


I'm a little surprised at the hair-splitting responses regarding extreme 
precision (Kevin was specifying 0.05 in/sec) and surface characteristics, all 
of which are true, but missed the simple point of how large would the dial have 
to be.



For a very rough first approximation, we know the shadow (or the apparent Sun) 
moves through 360° in 86,400 seconds.

This converts to about 7 x 10^-5 radians per second, and the tangent o that 
angle is the same, as far as matters.

Dividing 0.05 inch by 7 x 10^-5 gives a radius of a hair under 720 inches, or 
60 feet from the gnomon to the shadow surface.



Dave

(any maths errors can be attributed to responding before my second cup of 
coffee!)






From: Kevin Nute kn...@uoregon.edu
To: sundial@uni-koeln.de; Peter Ransom pran...@btinternet.com; JOHN DAVIS 
john.davi...@btopenworld.com
Sent: Tuesday, 6 August 2013, 21:38
Subject: Visibly Moving Gnomon Shadows





The movement of the gnomon shadow at the famous Samrat Yantra equitorial 
sundial in Jaipur is reputed to be clearly visible to someone standing near the 
projection surface. I've read it moves as fast as 1 mm/s, though obviously not 
all the time.  At a given latitude, say 40º N, can anyone suggest a simple 
formula for estimating how far a projection surface would need to be from a 
vertical or horizontal gnomon for the shadow to move at 1.27 mm/s (the 
practical lower threshold of perceptible movement) I wonder?   Or in other 
words, what's the smallest sundial you could build to see real-time movement of 
the gnomon shadow with the naked eye?


Kevin Nute
Professor of Architecture
University of Oregon
School of Architecture and Allied Arts
Eugene, OR 97403
USA
kn...@uoregon.edu








---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3392 / Virus Database: 3209/6556 - Release Date: 08/06/13



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3392 / Virus Database: 3209/6558 - Release Date: 08/07/13
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: ABBOTSFORD SUNDIAL

[Roger Bailey]

Hello Dennis,

The dial is not listed in the NASS registry or on Waymarking.com. Google only 
finds the Alice Morse Earle reference.

The geographical reference is vague. Menands is a small suburb of Albany NY, 3 
km up the Hudson River, halfway to Troy NY. There is a Hillside Cemetery 13 km 
due east near Poestenkill. Perhaps the dial is there.

Regards, Roger Bailey


From: Dennis Cowan
Sent: Tuesday, July 16, 2013 1:29 PM
To: sundial@uni-koeln.de
Subject: ABBOTSFORD SUNDIAL


On behalf of the Abbotsford Trust who look after Sir Walter Scott's home in the 
Scottish Borders, I am trying to source a photograph or sketch of the small 
horizontal sundial that was placed in the gardens in 1817.  The plinth and 
shaft are still in place but the dial has been missing for a number of years.  
In the book Sundials and Roses of Yesterday, Alice Morse Earle notes that an 
exact reproduction was placed in a garden at Hillside, Menand's, New York.  She 
shows a photo of the dial, but the detail cannot be seen.  Any assistance in 
obtaining a photo or sketch showing the detail of the dial or any detail about 
its description would be very much appreciated.

Regards

Dennis Cowan
www.sundialsofscotland.co.uk






---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3349 / Virus Database: 3204/6497 - Release Date: 07/16/13



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3349 / Virus Database: 3204/6498 - Release Date: 07/17/13
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Unicode characters for degrees, minutes, seconds above the decimalpoint.

[Roger Bailey]

Interesting Thanks Steve and Dave.

I use the Alt codes all the time for degrees, Greek and accents in Word. But my 
version of Word and my email program doesn't do the Com Dot trick. WordPad does.

While you are looking at System Tools for the Character Map or Notepad, try the 
scientific calculator. Use the Dec and Hex buttons to toggle back and forth 
between decimal and hexadecimal numbers.

Regards, Roger Bailey


From: Dave Bell
Sent: Saturday, July 06, 2013 10:12 AM
To: 'Sundial list'
Subject: RE: Unicode characters for degrees, minutes,seconds above the 
decimalpoint.


Good call, Steve!



With that in hand, you can easily (under Windows) enter both marks directly 
from the keyboard.

There is a means (perhaps not well known) supported by most MS and many non-MS 
programs, to enter any Unicode character.



Using the numeric keypad (NOT the top row of numbers above QWERY), hold down 
the Alt key while you enter the 4-digit decimal number that represents the 
Unicode character.

The Unicode digits, e.g. 00B0 for degree, are in hexadecimal so need to be 
“translated” to decimal first; for degree, that’s 0176.

So, entering Alt-0176 (you don’t type the dash) gives me °.



The Combining Dot Below is U-0323 and its decimal representation is 0803.

There are only a few you need to memorize or make a cheat sheet for.

I entered the notes below in Word, then pasted them here in Outlook.

Hopefully, they come through the maillist system intact!



Degree: ° (Alt-0176 = 00B0h)

With Comb Dot: °̣ (Alt-0176 Alt-0803 = 0323h)



Minute:  ‘̣

Second:  “̣



There are other useful characters, such as ± (Alt-0177), ² (Alt-0178), etc., 
but you can get them all from a Unicode table or from Windows’ Character Map.

(Start  All Programs  System Tools  Character Map)

Hovering over any character will give a pop-up hint with its Unicode 
representation.



Dave






From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Steve Lelievre
Sent: Saturday, July 06, 2013 5:25 AM
To: Sundial list
Subject: Re: Unicode characters for degrees, minutes, seconds above the 
decimalpoint.



On 06/07/2013 8:38 AM, Barry Wainwright wrote:

  It can be done, but how the characters are rendered depends very much on the 
application used to render them.



  Start  There are a block of unicode characters called Combining 
Diacritical Marks which are used to modify the preceding character. These 
characters include unicode character U-309A (UTF-8 E3 82 9A) which is a 
Combining Katakana-Hirangana Semi-voiced sound mark (but it looks very much 
like the degree symbol (U-00B0). When this character is 'typed' after a period, 
you get a character that is almost, but not quite, aligned:



  This is the unicode typed in as characters: 127.゚42




Perhaps also consider the required symbol followed by Combining Dot Below 
U-0323  ( see http://www.fileformat.info/info/unicode/char/323/index.htm )


For example in MS Word a ring, prime and double prime, each followed by 
Combining Dot Below give




Steve






---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3345 / Virus Database: 3204/6470 - Release Date: 07/06/13



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3345 / Virus Database: 3204/6470 - Release Date: 07/06/13
image002.jpg---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: A big new analemmatic sundial on Malta

[Roger Bailey]

Hello Paul and all,

Size doesn't matter. It is how you use your tool that is important. The shadows 
from people as gnomons are only so long. What is the use of an instrument when 
the indicator does not reach the scale? My NASS presentation How Long is My 
Shadow discusses this issue and offers a spreadsheet to calculate shadow 
lengths. See presentation 
http://www.walkingshadow.info/Publications/How%20Long.pdf The logic is now 
better expressed in Helmut Sonderegger's Alemma program. See 
http://www.helson.at/sun.htm Typically 5 m is a good size for an analemmatic 
sundial with a human gnomon.

There is a larger analemmatic sundial In Penticton British Columbia, Canada. 
Here is a link to the NASS registry..
http://sundials.org/index.php/component/sundials/onedial/240
This Penticton dial is 10.7 m x 19.8 m. It is a BIG sundial and can be seen 
with Google Earth at 49°27.189' N, 119°34.972' W. Although it was built in 1984 
by a well known sculptor with design advice from a professional astronomer, it 
is a poor design for many reasons. It is too big. The shadows fall well short 
of the hour posts. The large posts marking the solstices and equinox are 
displaced from the date line. It has an analemma shape marked with the dates to 
correct for the equation of time. This correction is popular but it does not 
work except at noon. The original sundial was made of wood and quickly rotted 
away on this exposed sandy beach. The current model using concrete may last 
longer. However it is an attractive popular feature on the beach in Penticton. 
Hopefully some using the dial will have the curiosity of a three year old and 
ask Why and remain curious after the typical adult response, Because, that 
is the way it is.

Sundials taught me to ask Why and seek answers beyond Because.

Regards,
Roger Bailey
Walking Shadow Designs





From: Sunclocks North America
Sent: Tuesday, June 18, 2013 6:26 PM
To: Sundial Mailing List
Subject: Re: A big new analemmatic sundial on Malta


Hello All,
  Congratulations to Mr. David Grima and to Stella Maris College for their 
accomplishment in building a beautiful Human Sundial, which is very nice and 
constructed with great looking materials and decorations.
  I would like to point out, however, that it is not the world's largest 
sundial, as the timesofmalta.com article has indicated, although it may be the 
worlds largest sundial 'made out of volcanic stone', as Mr. Grima was careful 
to point out in the video.
  There is at least one Human Sundial that I know of, located at 'Chatsworth 
House' in the UK that has a diameter of eight meters, or one meter larger than 
the Malta sundial.  In addition, the Chatsworth House Human Sundial is of a 
SunClock style that is corrected to indicate clock time instead of Sun Time, 
and which is also set-up to automatically adjust for Daylight Saving Time.
Thank you,
Paul Ratto
SunClocks North America
438-792-4823

On 2013-06-12, at 9:46 AM, Perit Alexei Pace a...@onvol.net wrote:


  Hello Jim,
  Thank you for your email,

  It was great working on this project (I made the calculations and concept 
design), which will hopefully help many students appreciate the beauty of 
science and art.
  Best regards,
  Alexei
  Malta


  On 12 June 2013 14:23, J. Tallman jtall...@artisanindustrials.com wrote:

Hello All,



Here is an interesting link to a video/story about a new analemmatic 
sundial installation on Malta – it seems that the dial type continues to 
spread, especially at schools, and this is a really nice one!




http://www.timesofmalta.com/articles/view/20130611/local/School-awaits-sundial-that-will-last-a-century.473347





Best,



Jim Tallman

www.spectrasundial.com

www.artisanindustrials.com

jtall...@artisanindustrials.com

513-253-5497




---
https://lists.uni-koeln.de/mailman/listinfo/sundial










---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3345 / Virus Database: 3199/6422 - Release Date: 06/18/13



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3345 / Virus Database: 3199/6422 - Release Date: 06/18/13
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: sundial spotting

[Roger Bailey]

I agree with Jack. The moon is a common feature on sundials in France, often as 
the radiant arc for the hour lines. I have see it as a useful style feature 
like the sun face or Beausoleil. Many of Zarbula's sundials use the crescent 
moon, more as a style feature than a symbolic one. Islamic symbol? Not in this 
case. Symbol of Mary? Perhaps but this is a a weak association. In my 
experience the sun / moon symbol is more common in other cultures like in Spain 
and Mexico than in France.

Zarbula also includes as options the sun, often inscribed with the religious 
IHS Christogram,  the name of Jesus, iota-eta-sigma, or ???.  Zarbula often 
included Masonic symbols like the compass and square. Strange exotic animals, 
birds? Whatever the customer wanted, Zarbula delivered. Whatever looked good 
and pleased the customer. His sundials were gnomonically correct, the rest was 
his exuberant folk art. All of Zarbula's existing dials are available on this 
Google Map. http://goo.gl/maps/QIF8n.

Regards, Roger Bailey

Everything I need to know, I learned from sundials.


From: Jack Aubert
Sent: Sunday, June 09, 2013 2:19 PM
To: 'Steve Lelievre' ; sundial@uni-koeln.de
Subject: RE: sundial spotting


As we learned on a BSS tour of the Perche region in northwestern France two 
years ago there are many sundials in that area that use the crescent moon as a 
decorative element.  Here are a few more of them:



http://michel.lalos.free.fr/cadrans_solaires/autres_depts/orne/perche_ornais/cs_de_mortagne.html



A booklet on local sundials published by the Perche tourism office asserts that 
the role of these decorative elements, including a few other shapes, is to stop 
the hour lines so that they don't converge to a point and lose definition, 
either by having the stone break up or the painted lines run together.   The 
crescent may just be something that became locally fashionable in that region 
of France when the dials were being constructed.   I think that is probably a 
more plausible explanation than looking too deeply for religious symbolism.



Jack Aubert





From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Steve Lelievre
Sent: Sunday, June 09, 2013 10:53 AM
To: sundial@uni-koeln.de
Subject: Re: sundial spotting



Hi all,

What, if any, is the significance of the recumbant crescent in this dial? 
Wikipedia describes crescents in art and symbolism, but its description relates 
mostly to the crescent as a symbol of Islam and in Christianity (Roman 
Catholic) as a symbol for Mary.

Is there any other or more specific meaning when used to furnish a dial? 
Specifically, a fully recumbant crescent as shown in this dial?

Steve



On 09/06/2013 9:11 AM, Fred Sawyer wrote:

  Karin,

  See a photo of the dial at

  
http://michel.lalos.free.fr/cadrans_solaires/autres_depts/orne/pays_d_alencon/cs_pays_d_alencon.html


  Fred Sawyer


  On Sunday, June 9, 2013, Karin ten Kleij-Meij karin...@yahoo.com wrote:
  
   Dear sundial people,
   Does the cadran solaire on this piece of art look familiar to you? :-)

   http://en.artscad.com/A.nsf/OPRA/SRVV-6D4TP2
   Best regards and wishing you a sunny day,
   Karin.




---https://lists.uni-koeln.de/mailman/listinfo/sundial

--
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.


--
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.





---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3343 / Virus Database: 3199/6396 - Release Date: 06/09/13



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3343 / Virus Database: 3199/6397 - Release Date: 06/09/13
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Sundials along the Camino de Santiago de Compostela

[Roger Bailey]

Hello Fabio,

I have added six sundials to the sundial atlas, ES1247, to ES1251. They are all 
along the Camino. Please add them your Camino path.

Regards, Roger Bailey



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3272 / Virus Database: 3162/6265 - Release Date: 04/22/13
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Sundials along the Camino de Santiago de Compostela

[Roger Bailey]

Hello Fabio,

I agree with your comment. I should have provided more specific location 
information. Some years ago I provided these pictures to Piers Nicholson to add 
to his Camino Sundial Tour  I did not provide a link to his site as it was 
hacked recently. Google sundials on the internet and be wary of the warning 
This site could damage your computer. I gave away my guide books and maps so 
it will take a while to get good location data. Check the Fabio Savian's 
Sundial Atlas as I suspect all these dials are on his trail.

Roger Bailey






From: f...@solariameridiane.it
Sent: Saturday, April 20, 2013 12:27 AM
To: Sundial sundiallist
Subject: Re: Sundials along the Camino de Santiago de Compostela


Hello
I visited the album but I have not figured out how I can find them on a map...
I have not found information on their location, only pictures. How can we 
understand where are they located?
Fabio Garnero


Il giorno 19/apr/13, alle ore 19:56, Roger Bailey ha scritto:


  Hello Dennis,

  We hiked major sections of the Camino in Spain five years ago. Pictures of 
the sundials we viewed are available at this link.
  
https://picasaweb.google.com/rtbailey101/CaminoSundials?authuser=0authkey=Gv1sRgCK6bvri9_9Gu6gEfeat=directlink

  The sundial locations include Leon, Astorga, Iron Cross, Boente, Villafranca 
and Santiago. The hardest dial to find was the large stone block with old 
sundials on three faces. A patio restaurant blocks access.

  Enjoy the trip. I hope you will have better weather than we did in 2008

  Regards, Roger Bailey


  From: Dennis Jordan
  Sent: Wednesday, April 17, 2013 5:42 PM
  To: sundial@uni-koeln.de
  Subject: Sundials along the Camino de Santiago de Compostela


  I have followed this list serve for some time, although I have not been an 
active participant. I have very much appreciated the passionate discussions.

  Does anyone know of a resource way marking sundials close by or on the Camino 
de Santiago de Compostela?

  I will be walking this path in a few months and would love the opportunity to 
mix my interests.

  Thanks for the opportunity to ask.


  Dennis Jordan



--



  ---
  https://lists.uni-koeln.de/mailman/listinfo/sundial





--



  No virus found in this message.
  Checked by AVG - www.avg.com
  Version: 2013.0.3272 / Virus Database: 3162/6252 - Release Date: 04/17/13

  No virus found in this message.
  Checked by AVG - www.avg.com
  Version: 2013.0.3272 / Virus Database: 3162/6256 - Release Date: 04/19/13

  ---
  https://lists.uni-koeln.de/mailman/listinfo/sundial









---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3272 / Virus Database: 3162/6258 - Release Date: 04/19/13



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3272 / Virus Database: 3162/6258 - Release Date: 04/19/13
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Sundials along the Camino de Santiago de Compostela

[Roger Bailey]

Hello Denis, Fabio and all,

Let me supplement the picture link for sundials on the Camino with location 
data and descriptions. Most of the sundials shown I waymarked in 2010 with 
pictures, locations and descriptions. Click on the waymark hypertext to bring 
up the link. For those on text only, go to www.waymarking.com and search on the 
waymark code, WM.

Leon Cathedral, WM8929, 42°35.951, 5°34.000
Astorga Cathedral, WM8944, 42°27.452, 6°3.420
Cruz de Fierro, WM8974, 42°29.347, 6°21.681
Boente Church, WM8AZJ, 42°54.972, 6°4.668
San Francisco Villafranca, WM8AZF, 42°36.566, 6°48.568
Caixa Galacia, WM8AZD, 42°36.452, 6°48.511

The dials in Santiago in the photo link, I have not yet waymarked or posted on 
the sundial atlas . There are three sundials visible in the courtyard of the 
University Library, Biblioteca de Santiago de Compostela, near the cathedral at 
42°52.763, 8°32.723. There are also three on the stone block overshadowed by 
the patio restaurant of the Parador de Santiago, Hostal doe Reis Catolicos, 
42°52.859, 8°32.782. Again this is near the cathedral, on the other side of the 
square. On Google Earth you can see the tent of the patio restaurant crowding 
the stone block with the old sundials.

Most of these are in the sundial atlas Camino Tour. Fabio has a few I do not. I 
have a few he missed. There are opportunities to find more to fill out this 
aspect of the Camino de Santiago, the ancient pilgrimage walk, the Way of St 
James.

Enjoy the journey,

Roger Bailey


From: Dennis Jordan
Sent: Wednesday, April 17, 2013 5:42 PM
To: sundial@uni-koeln.de
Subject: Sundials along the Camino de Santiago de Compostela


I have followed this list serve for some time, although I have not been an 
active participant. I have very much appreciated the passionate discussions.



Does anyone know of a resource way marking sundials close by or on the Camino 
de Santiago de Compostela?



I will be walking this path in a few months and would love the opportunity to 
mix my interests.



Thanks for the opportunity to ask.





Dennis Jordan






---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3272 / Virus Database: 3162/6252 - Release Date: 04/17/13



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3272 / Virus Database: 3162/6261 - Release Date: 04/20/13
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Sundials along the Camino de Santiago de Compostela

[Roger Bailey]

Hello Dennis,

We hiked major sections of the Camino in Spain five years ago. Pictures of the 
sundials we viewed are available at this link.
https://picasaweb.google.com/rtbailey101/CaminoSundials?authuser=0authkey=Gv1sRgCK6bvri9_9Gu6gEfeat=directlink

The sundial locations include Leon, Astorga, Iron Cross, Boente, Villafranca 
and Santiago. The hardest dial to find was the large stone block with old 
sundials on three faces. A patio restaurant blocks access.

Enjoy the trip. I hope you will have better weather than we did in 2008

Regards, Roger Bailey


From: Dennis Jordan
Sent: Wednesday, April 17, 2013 5:42 PM
To: sundial@uni-koeln.de
Subject: Sundials along the Camino de Santiago de Compostela


I have followed this list serve for some time, although I have not been an 
active participant. I have very much appreciated the passionate discussions.



Does anyone know of a resource way marking sundials close by or on the Camino 
de Santiago de Compostela?



I will be walking this path in a few months and would love the opportunity to 
mix my interests.



Thanks for the opportunity to ask.





Dennis Jordan






---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3272 / Virus Database: 3162/6252 - Release Date: 04/17/13



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3272 / Virus Database: 3162/6256 - Release Date: 04/19/13
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Today's Google Banner - More

[Roger Bailey]

Hi Jack,

I am with you, cute but so what. I appreciate Google noting Euler's 306th 
birthday but again so what. I use to appreciate Google and their do no 
evil philosophy. This is cute but no longer respected in the monetization 
of searches, links and privacy. Things were better in the old days.


O God! methinks it were a happy life
To be no better than a homely swain;
To sit upon a hill, as I do now,
To carve out dials quaintly, point by point,
Thereby to see the minutes how they run,
How many make the hour full complete;
How many hours bring about the day;
How many days will finish up the year;
How many years a mortal man may live.

Shakespeare, Henry VI contemplating battle.

Regards Roger Bailey




--
From: Jack Aubert j...@chezaubert.net
Sent: Monday, April 15, 2013 7:05 PM
To: 'Frank King' frank.k...@cl.cam.ac.uk; sundial@uni-koeln.de
Subject: RE: Today's Google Banner - More

But why his 306th birthday?  What is the significance of 306?  Am I 
missing

something obvious?

Jack


-Original Message-
From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Frank 
King

Sent: Monday, April 15, 2013 4:30 AM
To: sundial@uni-koeln.de
Subject: Today's Google Banner - More

I should, of course, have added:

  Happy Birthday to Leonhard Euler

306 years old today and still going
strong!

It is a happy coincidence that he
should have been born on the day
that the Equation of Time changes
sign.

Frank King
Cambridge, UK

---
https://lists.uni-koeln.de/mailman/listinfo/sundial


--
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.



--
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.

---
https://lists.uni-koeln.de/mailman/listinfo/sundial



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3272 / Virus Database: 3162/6247 - Release Date: 04/15/13




-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3272 / Virus Database: 3162/6247 - Release Date: 04/15/13

---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Horas benedictinus

[Roger Bailey]

Here is a quotation from the Rule of St Benedict.

CHAPTER XVI,How the Work of God Is to Be Performed during the Day
As the Prophet saith: Seven times a day I have given praise to Thee 
(Psalms 119:164), this sacred sevenfold number will be fulfilled by us in 
this wise if we perform the duties of our service at the time of Lauds, 
Prime, Tierce, Sext, None, Vespers, and Complin;


These times were based on the position of the sun and shadow lengths: dawn, 
sunrise, mid-morning, noon, mid-afternoon, sunset and nightfall. Moslem 
prayer times used the same time system but generally dropped the sunrise and 
mid-morning prayers.


Regards, Roger Bailey


--
From: Darek Oczki dhar...@o2.pl
Sent: Wednesday, April 10, 2013 6:31 AM
To: sundial@uni-koeln.de
Subject: Horas benedictinus

An archeologist discovered a very old sundial on a church in a small 
village in south of Poland. It is a scratch dial with no gnomon nor any 
hour markings except for a few lines and a hole in the middle. As good as 
I could I tried to describe this kind of dials giving other examples found 
in this area. He seemed to be satisfied however he asked if the dial could 
be related to HORAS BENEDICTINUS. This terms is new to me. Could someone 
help me understand this, please? What does it refer to?


--
Best regards
Darek Oczki
52N 21E
Warsaw, Poland

GNOMONIKA.pl
Sundials in Poland
http://gnomonika.pl
---
https://lists.uni-koeln.de/mailman/listinfo/sundial



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3272 / Virus Database: 3162/6235 - Release Date: 04/09/13




-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3272 / Virus Database: 3162/6236 - Release Date: 04/10/13

---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Horas benedictinus

[Roger Bailey]

Thank you Mario, for this insight.  I did not read the whole book, just the 
excerpts. These are useful, correct but incomplete information. Perhaps I 
should read the the 41th, the 42nd and the 48th. Or perhaps not. I do not 
live by Benedict's Rule, the Divine Office, Moslem Prayer times etc but by 
the natural circadian and solar rhythms.


Regards, Roger Bailey

--
From: Mario Arnaldi marna...@libero.it
Sent: Wednesday, April 10, 2013 10:37 AM
To: sundial@uni-koeln.de
Subject: Re: Horas benedictinus

These times were based on the position of the sun and shadow lengths: 
dawn, sunrise, mid-morning, noon, mid-afternoon, sunset and nightfall. 
Moslem prayer times used the same time system but generally dropped the 
sunrise and mid-morning prayers.



If we talking on the Rule of St. Benedict, this is not correct Roger.
Ch. 16th gives only general notices about the Opus Dei (the Work of God or 
the Divine Office). The Rule gives times along the year and it is very 
clear about the moments for Prayers. Chapters to be read are the 41th, the 
42d and the 48th. But This is only for the Benedict's Rule. Other Rules 
presents different times.


Mario

---
https://lists.uni-koeln.de/mailman/listinfo/sundial



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3272 / Virus Database: 3162/6236 - Release Date: 04/10/13




-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3272 / Virus Database: 3162/6237 - Release Date: 04/10/13

---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: A glass in Taiwan

[Roger Bailey]

Sundials on glass surfaces are challenging. The ideal surface to show a shadow 
is matte and opaque. Shadows cannot be seen on clear glass or mirrors. With 
semi-opaque glass, a shadow can be seen on both the sunny side and underside. 
But many factors can lower the contrast: reflection, translucence, opacity as 
well as the usual sundial problems with haze and penumbra fuzziness. I am 
advising a client on large vertical declining sundial on a glass curtain wall. 
The shadow is to be visible on both the sunny outside and the dim inside 
surface of the glass. On this project frit* is to be silk screened and fused 
onto the glass to provide the pattern, lines and desired opacity. It is an 
interesting design project. Stay tuned.

Roger Bailey
Walking Shadow Designs

*see http://en.wikipedia.org/wiki/Frit#Modern_uses_of_frit


From: Chiu ?,Chi lian 
Sent: Monday, March 25, 2013 10:21 PM
To: Reinhold Kriegler ; Sundial sundiallist 
Subject: Re: A glass in Taiwan


Dear Reinhold, 
  
Sorry for the smallness of the picture attached in the last mail for I was 
worrying about the size limit last night.


The above ground construction of the landmark body, a pair of strange shaped 
art pieces, is just half done up to now. That is only one piece of the pair is 
very close to the finishing as shown in the attachment of this mail. 


Unfortunately, that is not the piece on which the glass sundial will be set up. 
The dial will be on the other one, which will be erected next month. The yellow 
sundial in the attached picture is just for giving you an idea how it will be 
up on the other coming piece of the pair. 


When the landmark structure is finished, people walking outside the structure 
can't see the dial because their sights are blocked by the arms of the 
structure. (It's done in this way deliberately to keep the outside view of the 
landmark as a piece of art.) When people walk inside the structure area, 
they'll find a dial above their head surprisingly. They can't see the gnomon 
plate but only its shadow on a sandblasted glass plate where only the hour 
lines are totally transparent. 


Financially speaking, the dial is built by a cooperation who won the government 
commission contract to build the landmark. Yes, I helped them in proposing the 
idea of moving the dial from the narrow, over-crowded ground up to the sky, in 
calculations and model examination.
From now, I will make sure they install it right.


For more information you may try 
http://blog.xuite.net/nycl.chiu/blog/63325424
and
http://blog.xuite.net/nycl.chiu/blog/66026604
They are written in Chinese, but I think the pictures there will tell you 
everything essential.


Your homepage is great. I wish I could have one like yours. 


Regards, 


  ChiLian
  N25, E125



2013/3/26 Reinhold Kriegler reinhold.krieg...@gmx.de

  Dear ChiLian Chiu!



  Thank you very much for this very rare information from Taiwan.

  Did you build this sundial? I do not understand quite well how it works, but 
perhaps will see with a bigger image…

  Would it be possible to get a higher resolution picture in order to see the 
details better?



  I am sure you will soon get several answers from US-American glass sundial 
fans!



  Good wishes to you!

  Reinhold Kriegler



  You are invited to have a look at my homepage www.ta-dip.de !



  * ** ***  * ** ***

  Reinhold R. Kriegler

  Lat. 53° 6' 52,6 Nord; Long. 8° 53' 52,3 Ost; 48 m ü. N.N.  GMT +1 (DST +2)  
 www.ta-dip.de

  http://de.youtube.com/watch?v=XyCoJHwzzjUfmt=18

  http://www.ta-dip.de/dies-und-das/r-e-i-n-h-o-l-d.html
  http://www.ta-dip.de/salon-der-astronomen/musik-im-salon-der-astronomen.html

  -Ursprüngliche Nachricht-
  Von: sundial [mailto:sundial-boun...@uni-koeln.de] Im Auftrag von Chiu ªô,Chi 
lian
  Gesendet: Montag, 25. März 2013 19:41
  An: sundial@uni-koeln.de
  Betreff: A glass in Taiwan



  Hi, dear members:



  A new glass sundial, close to horizontal type, but inclined due west by 10 
degrees, is going to be installed in JiaYi, Taiwan next month. 

  The dial will be put up to fit in an empty space, 6 meter high from the 
ground, of a landmark structure, which is shown in the attached diagram. The 
yellow  oval-shaped area in the diagram is the place the dial will be 
installed. To view the shadow of the gnomon on the glass dial plate, one has to 
be under it and look upward to his top. To this point, it is unlike those 
normal window dials, which one just needs to look front or with an angle not 
too high.



  This is what beyong my knowledge: is there any dial of this kind (glass and 
look upward to one's top) around already? 

  Please help. 



  Best regards,



  ChiLian Chiu

   N25, E125,  Hsinchu, Taiwan








---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: equation of time sundial

[Roger Bailey]

Hello Ken,

The examples using an analemma shaped gnomon that project the shadow the 
equatorial line do what you want. An improvement could be a wire stretched 
along the centerline of the gnomon in Willy's Spanish example. This would 
provide solar time. The two values of the EQT at that declination would be the 
shadow line of the aperture. Thus the two possible values of EQT could be read 
directly without knowing the the date. 

Regards, 
Roger Bailey
Walking Shadow designs. 

  


From: Ken Baldwin 
Sent: Sunday, February 03, 2013 2:19 PM
To: peter.ma...@adelaide.edu.au 
Cc: sundial 
Subject: Re: equation of time sundial


Hi guys, 


Thanks for your responses.


I'm not trying to read the EOT-adjusted time from the device, I want to read 
the actual EOT value itself for that date. For example, on Aug 9th, at any 
daylight hour, I'd like to be able to read, say, -5.5 min. Maybe I'm 
misunderstanding, but do I get that from these analemmic gnomons or hour lines? 


I'm suggesting something like Peter's design, but with the hour lines removed, 
and the date lines labelled with the EOT value (-15 min - 15 min).


I understand Simon's point that the altitude of the sun is ambiguous between 
two dates, so perhaps it would have to be split into two plates (like 
half-analemmas). Of course, this requires the user to know which 6 month period 
of the year they are in, which partially defeats the purpose of not needing to 
know the date :-)


Ken



On Sun, Feb 3, 2013 at 2:14 PM, Peter Mayer peter.ma...@adelaide.edu.au wrote:

  Hi Ken,

  Here's another example of a dial which may interest you.  This is my 
adaptation of a brilliant dial coded by Steve Lelievre.  To fit the size limit 
on this list, I've had to squeeze the image greatly, but you should be able to 
grasp the principle of the dial: each month is a separate concentric circle.  
Between month lines one must interpolate the date to read the civil time. 


  best wishes,

  Peter

  On 4/02/2013 6:32 AM, Ken Baldwin wrote:

Hello,

I'm a new list member, and have a beginner question:

Are there examples of sundials whose sole (or primary) purpose is to
compute the Equation of Time for the current date?

- I know that this information is often provided as a graph in the
furniture, but why should I have to know the date and perform the
look-up manually? Can't I use the position of the sun to do the
computation for me?

- I know that the EOT correction can be incorporated into the layout of
(some) hour lines, but I'm more interested in having dials which show
true solar time. I'd like a separate device dedicated to computing the EOT.

- I know that I can construct an analemmic noon mark to show the EOT for
that day, since it's simply the east-west component of the analemma, but
I'd like a design that can be read at any daylight hour.

It seems to me that it should be possible to build such a dial, since
the EOT is a function of date, and date lines can be read from many
sundials. In principle, I can just re-label the date lines with
corresponding EOT values and interpolate.

I hope that makes sense. But since I haven't seen anything like that in
introductory sundial books, I must be missing something... Is it that
the shadow length can't be read accurately enough to get a reasonably
precise EOT estimate? Or is it just too hard to make a readable layout,
given that solar altitude is ambiguous between two dates, and that the
component of the EOT due to the eccentricity of the earth's orbit is out
of phase with the equinoxes and solstices?

Thanks in advance,
Ken Baldwin
Corvallis, OR USA




---
https://lists.uni-koeln.de/mailman/listinfo/sundial



  -- 
  --
  Peter Mayer
  Politics Department
  The University of Adelaide, AUSTRALIA 5005
  Ph : +61 8 8313 5609
  Fax : +61 8 8313 3443
  e-mail: peter.ma...@adelaide.edu.au
  CRICOS Provider Number 00123M
  ---

  This email message is intended only for the addressee(s) and contains 
information that may be confidential and/or copyright. If you are not the 
intended recipient please notify the sender by reply email and immediately 
delete this email. Use, disclosure or reproduction of this email by anyone 
other than the intended recipient(s) is strictly prohibited. No representation 
is made that this email or any attachments are free of viruses. Virus scanning 
is recommended and is the responsibility of the recipient.








---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG

Re: I found out (graphic) a theorem

[Roger Bailey]

Hi Dave,

I agree with your logic, looking at the equatorial disc where the hour angles 
are true, equal to 15° per hour and the gnomon line as a point, the same point 
on this plane as the intersection point discussed. The gnomon point becomes a 
line in other projections, but the geometric point projects remains as an 
intersection point of the hypotenuse lines of hour triangles 6 hours apart. 

This drawing evoked in my mind the construction techniques of Durer and 
Zarbula, techniques of descriptive geometry now bypassed by trig 
transformations in computer programs, useful but only understood by their 
creators. I appreciate Fer de Vries for making his logic and not just his 
design program available. See A Universal Method to Compute Flat Sundials 
http://www.de-zonnewijzerkring.nl/eng/index-vlakke-zonw.htm

Regards,
Roger Bailey
Walking Shadow Designs

From: Dave Bell 
Sent: Sunday, February 03, 2013 4:51 PM
To: sundial@uni-koeln.de 
Subject: RE: I found out (graphic) a theorem


I believe I may have the answer here. Can't formally prove it yet, but it makes 
sense.

 

Returning to the most basic sundial, the equatorial, the hour angles are equal, 
and hours differing by 6 have hour angle lines at 90°.

Inscribing any right triangle in a circle (the equatorial plane), the 
hypotenuse of the triangle will always be a diameter.

All diameters intersect in a single point, the center of the circle.

 

When the circular equatorial dial is projected on a non-equatorial plane, the 
equatorial circle becomes an ellipse.

The hour angle pair chords must still intersect, even though the angles at the 
origin of the dial are no longer necessarily right angles.

The common intersection point on the (horizontal, e.g.) dial is the projection 
of the center of the equatorial dial.

 

Dave

 




From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Willy Leenders
Sent: Sunday, February 03, 2013 2:11 PM
To: Sundial sundiallist
Subject: I found out (graphic) a theorem

 

In his book Die Sonnenuhr und ihre Theorie (The sundial and his theory) Jörg 
Meyer writes on page 200 (my English translation):

 

I found the following remarkable theorem  in the book of Heinz Schilt. 'Ebene 
Sonnenuhren' (Plane sundials)

 

Through the point P where all the hour lines of any sundial come together, a 
circle is drawn.

The center M and the radius of the circle are irrelevant.

The hour lines whose hour angle differ from each 6 hours or 90 ° were grouped 
into pairs.

The points where the hour lines of a pair intersect the circle, are connected 
with a chord (a straight line joining the ends of an arc )

Then is applicable: all these chords pass through a common point Q.

 



 

 

In the study of this case and assuming that the projection of a circle is an 
ellipse and vice versa,  I found out (graphic) the theorem:

 

Of all right triangles, inscribed in an ellipse, of which the right angle point 
(point P) is common, the hypotenuses intersect in the same point (point S).


See drawing.

 

 

I found that theorem never formulated, certainly no proof.


Who can prove this theorem?

 



 

 

 

 

 

Willy Leenders

Hasselt in Flanders (Belgium)

 

Visit my website about the sundials in the province of Limburg (Flanders) with 
a section 'worth knowing about sundials' (mostly in Dutch): 
http://www.wijzerweb.be

 

 

 

 






 






---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.2897 / Virus Database: 2639/6078 - Release Date: 02/03/13
image001.jpgimage002.jpg---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Forensic Shadows..

[Roger Bailey]

Perhaps the quote should be too short for February as shadows at any time 
the sun is up in February are longer on a horizontal surface than in July at 
the same time of day.


Regards, Roger Bailey

--
From: Barry Wainwright bar...@mac.com
Sent: Wednesday, January 30, 2013 3:40 PM
To: Sundial list sundial@uni-koeln.de
Subject: Forensic Shadows..

As part of a speeding case which came to court last July 2011, he 
provided CCTV footage from a system at his home showing him and his 
Mitsubishi, date-stamped with the time he was said to have been speeding.
However, police experts noticed the shadows in Moore's driveway on the 
CCTV were too long for February.


http://www.bbc.co.uk/news/uk-england-devon-21267386

---
https://lists.uni-koeln.de/mailman/listinfo/sundial



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.2890 / Virus Database: 2639/6064 - Release Date: 01/28/13


---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Interesting sundial

[Roger Bailey]

Hi Mike,
I saw a small screw attaching the disc and assumed it allowed a longitude 
adjustment. If it is just an attaching screw, perhaps the owner could drill and 
tap a hole suitable for their longitude and even DST. The EQT graph is 
universal with no longitude offset. I believe the similar dials that Tony made 
for his grandkids were designed to be universal.

Regards, Roger


From: jmikes...@ntlworld.com 
Sent: Saturday, January 26, 2013 1:27 PM
To: R Wall ml ; John Carmichael ; Sundial Mailing List 
Subject: Re: Interesting sundial


I’ve always thought that the “summer” side of dials like this should show 
daylight saving time.
Unfortunately, the authorities refuse to change the clocks at each equinox, so 
there would be some offset.

BTW, I have one of these “Tony Moss equatorials” and mine is adjustable for 
latitude, but not longitude as someone suggested.


Mike Shaw
53º 22' North 03º 02' West
www.wiz.to/sundials
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.2890 / Virus Database: 2639/6058 - Release Date: 01/25/13






---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.2890 / Virus Database: 2639/6056 - Release Date: 01/25/13
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Interesting sundial

[Roger Bailey]

Hello Douglas,

Your original post deserved a response. The sundial has an equatorial disk 
inscribed on both sides with hour lines at 15° intervals. In the spring and 
summer, the upper side of the dial is in the sun. In the fall and winter the 
sun shines on the lower side. On the equinox, the sun lines up exactly with the 
disc. The gnomon is a pin oriented to the polar axis that sticks out on both 
sides. The dial is adjustable for latitude and longitude. It is a simple but 
ancient design, similar to the bronze ring in the Great Hall in Alexandria that 
determined the length of the solar and stellar years, differing due to 
precession. This is described in Ptolemy's Almagest, still considered the 
great book by many of us.

This specific sundial is significant as described by John in his original note 
on 4 Jan. Many years ago, NASS gave me the Sawyer Dialing Prize which was a 
beautiful and sturdy little brass equatorial dial made by The Great Tony Moss 
himself. Sadly, it has set on my shady workbench, much loved but unused for all 
these years. I had no sunny window available and no good place outside- until 
now! I thought what a great idea! I’ll use my Sawyer Dialing Prize Sundial as a 
miniature monumental sundial on the railroad. So I glued it on top of a stone 
pinnacle by the Trolley Station. Looks great and works just fine. Thanks Tony.

I am also pleased to own a different custom Lindisfarne Sundial by Tony Moss, a 
great craftsman, teacher and also a Sawyer Prize winner. As a long time college 
and friend, again, thanks Tony,

This list has been active for about 20 years as a way of sharing our interest 
in sundials with old friends and new. In general we are quite tolerant and open 
to sharing information. In 20 years only a couple people have been struck off 
the list for persistent annoying misbehavior. Let's keep it that way, 
tolerating the occasional interesting off topic excursions.

Regards, as usual,

Roger Bailey


From: Douglas Vogt 
Sent: Friday, January 25, 2013 10:31 AM
To: sundial@uni-koeln.de 
Subject: Interesting sundial


In a previous post (24 Jan. 2013), I thought a sundial in a photo was neat and 
wondered if there were plans for it. As a relative newcomer, I don't even know 
what kind it is.


That post was apparently completely misinterpreted by an irritable being as 
something having to do more with those things that run on steel rails and not 
sundials. I merely responded to the subject line. My post and the response 
caused further OTs, for which I apologize. 



In any case, it is a neat sundial and I'd like to know more about it if the 
designer is not too P.O.d to respond.
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Analemmatic sundial

[Roger Bailey]

--
From: rPauli rpa...@speakeasy.org
Sent: Sunday, January 13, 2013 12:00 AM
To: Roger Bailey rtbai...@telus.net
Cc: h.sondereg...@utanet.at; sundial@uni-koeln.de
Subject: Re: Analemmatic sundial


Isn't there an optimal sundial design for equator regions?


Hi Richard and all,

The Greeks solved this with the hemispherium and scafe dials. The 
hemispherium is a spherical bowl with a point gnomon. The celestial sphere 
of the sky above is projected through the point onto hour and declination 
lines marked in the bowl.  The curved bowl provides uniform scaling.
A point gnomon above a horizontal  or polar plane works as well but when the 
sun is low the shadow race off on a tangent. The scafe is a section of the 
hemisphere, the relevant section based on the suns declination.  Fer De 
Vries has  on his website design information for a hemisherium.

Copy and paste this url:  http://www.dse.nl/~zonnewijzer/hemisph.htm

Even a horizontal sundial with a polar gnomon works in the tropics. 
Generally just a section of the polar gnomon is used and this is raised and 
supported above the plane.


Regards, Roger Bailey 


---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Analemmatic sundial

[Roger Bailey]

Perhaps this is why there are so few analemmatic sundials in the tropics. I 
do not know of any except for the one I built years ago at 20.4°, or 3° into 
the tropics. This dial was just markings in the sand on a beach, as 
impermanent as all messages on a beach.


For similar reasons there are few vertical sundials in the tropics. The 
shadows are too long from the gnomon and any overhanging eaves. The reversal 
mid-day to the north side in the spring and summer is another design 
complexity.


In any case it is interesting to explore, as Frank has, how latitude changes 
the designs.


Regards,
Roger Bailey
from the polar side of temperate zone, N 48.6

--
From: Frank King frank.k...@cl.cam.ac.uk
Sent: Saturday, January 12, 2013 3:14 AM
To: Donald Christensen dchristensen...@gmail.com
Cc: vk...@optusnet.com.au; Sundial Mailing Mailing List 
sundial@uni-koeln.de

Subject: Re: Analemmatic sundial


Dear Donald,

You wrote...


Brilliant idea Roderick!

I put both animations on my website.
Each one has a label under it stating
which hemisphere it's for...


Whoa!  Hold on a moment!

The fun has only just begun...

Have you thought what happens in the
tropics?

Someone living at 20 degrees north (well
into the northern hemisphere) will not
be impressed by your northern hemisphere
animation around the summer solstice.
This is what happens:

1.  The sun rises somewhat to the
north of due east (no surprise
so far).

2.  It heads south for a while and
therefore goes round clockwise
(still no surprise).  Then...

3.  Suddenly it reverses direction
and goes ANTI-clockwise, and it
stays running that way...

4.  ...through noon and...

5.  well into the afternoon.  Then...

6.  Suddenly it reverses direction
again and goes CLOCKwise until...

7.  Sunset.

Phew!  Quite a day, eh?

You get a hint of what's going on once
you draw out an analemmatic sundial for
20 deg. north.  You will see that the
date line is LONGER than the minor axis
of the hour-point ellipse.

There are two times of day when the line
from the summer solstice point (say) makes
a tangent to the ellipse.  These are the
times when the direction reverses.

I wonder how many readers think that
I am kidding :-))

Life can get tough when you start thinking
about special cases!

Frank King
Cambridge, U.K.

---
https://lists.uni-koeln.de/mailman/listinfo/sundial



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.2890 / Virus Database: 2638/6027 - Release Date: 01/12/13


---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Analemmatic sundial

[Roger Bailey]

Hello Helmut,

Thank you, Helmut, for this graphical demonstration on the problems with 
tropical sundials on certain dates. The hours cannot be discriminated. The 
declination line and hour circle can coincide. Height of the gnomon and 
length of the shadow are of no help as analemmatic sundials are are two 
dimensional so height doesn't matter.  This is why I developed and 
distributed a spreadsheet and gave a presentation in 1999 on How Long is my 
Shadow: The Use of Declination Lines in the Design of Analemmatic Sundials. 
After that we successfully collaborated on improving the software and you 
developed an excellent stand alone design programs that easily provides 
information like your pdf sketch. Now all sundial designers can review how 
parameters interact. Sometimes analemmatic sundials don't work in the 
tropics.


Regards, Roger Bailey



--
From: Helmut Sonderegger (Tele2) h.sondereg...@utanet.at
Sent: Saturday, January 12, 2013 2:32 PM
To: sundial@uni-koeln.de
Subject: Re: Analemmatic sundial


This as a printout with my software for an analemmatic sundial at
Northern latitude 20 deg and with shadow path of a person on Jun 1st. I
hope the attachment comes trough (52 kB).

Best regards
Hlemut

Am 12.01.2013 19:11, schrieb Roger Bailey:

Perhaps this is why there are so few analemmatic sundials in the
tropics. I do not know of any except for the one I built years ago at
20.4°, or 3° into the tropics. This dial was just markings in the sand
on a beach, as impermanent as all messages on a beach.

For similar reasons there are few vertical sundials in the tropics.
The shadows are too long from the gnomon and any overhanging eaves.
The reversal mid-day to the north side in the spring and summer is
another design complexity.

In any case it is interesting to explore, as Frank has, how latitude
changes the designs.

Regards,
Roger Bailey
from the polar side of temperate zone, N 48.6

--
From: Frank King frank.k...@cl.cam.ac.uk
Sent: Saturday, January 12, 2013 3:14 AM
To: Donald Christensen dchristensen...@gmail.com
Cc: vk...@optusnet.com.au; Sundial Mailing Mailing List
sundial@uni-koeln.de
Subject: Re: Analemmatic sundial


Dear Donald,

You wrote...


Brilliant idea Roderick!

I put both animations on my website.
Each one has a label under it stating
which hemisphere it's for...


Whoa!  Hold on a moment!

The fun has only just begun...

Have you thought what happens in the
tropics?

Someone living at 20 degrees north (well
into the northern hemisphere) will not
be impressed by your northern hemisphere
animation around the summer solstice.
This is what happens:

1.  The sun rises somewhat to the
north of due east (no surprise
so far).

2.  It heads south for a while and
therefore goes round clockwise
(still no surprise).  Then...

3.  Suddenly it reverses direction
and goes ANTI-clockwise, and it
stays running that way...

4.  ...through noon and...

5.  well into the afternoon.  Then...

6.  Suddenly it reverses direction
again and goes CLOCKwise until...

7.  Sunset.

Phew!  Quite a day, eh?

You get a hint of what's going on once
you draw out an analemmatic sundial for
20 deg. north.  You will see that the
date line is LONGER than the minor axis
of the hour-point ellipse.

There are two times of day when the line
from the summer solstice point (say) makes
a tangent to the ellipse.  These are the
times when the direction reverses.

I wonder how many readers think that
I am kidding :-))

Life can get tough when you start thinking
about special cases!

Frank King
Cambridge, U.K.

---
https://lists.uni-koeln.de/mailman/listinfo/sundial



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.2890 / Virus Database: 2638/6027 - Release Date:
01/12/13


---
https://lists.uni-koeln.de/mailman/listinfo/sundial











---
https://lists.uni-koeln.de/mailman/listinfo/sundial







-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.2890 / Virus Database: 2638/6027 - Release Date: 01/12/13 


---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Analemmatic sundial

[Roger Bailey]

Yes, there is a world of difference. I was recently in New Zealand and it took 
some time to get my head around the difference for sundials. South is their 
reference pole and the numbers do go the other way around. It is interesting a 
northern designed vertical south facing sundial is identical to a southern 
horizontal dial for the co-latitude. I found a number of good sundials in New 
Zealand but didn't find any that exploited the above advantage. 

Thanks Rosaleen Robertson of the New Zealand Sundial Association 
(www.sundials.org.nz) for your assistance.

Regards, Roger Bailey 
@ 48.6° north again


From: Willy Leenders 
Sent: Friday, January 11, 2013 2:38 AM
To: Willy Leenders 
Cc: sundial@uni-koeln.de 
Subject: Re: Analemmatic sundial






My comment is valid only for the northern hemisphere 




Willy Leenders
Hasselt in Flanders (Belgium)















Op 11-jan-2013, om 11:20 heeft Willy Leenders het volgende geschreven:


  Donald, 


  A nice idea.


  If you want to display the progress of the shadow from morning to evening, 
the movement must be in clockwise and not the rverse as in the animated image. 


  Willy Leenders
  Hasselt in Flanders (Belgium)


  Visit my website about the sundials in the province of Limburg (Flanders) 
with a section 'worth knowing about sundials' (mostly in Dutch): 
http://www.wijzerweb.be













  Op 11-jan-2013, om 03:32 heeft Donald Christensen het volgende geschreven:


Hi all

I just had a cartoonist work on the logo for my website. The idea is that I 
wanted to put it in the footer of my emails. I will eventually put it in the 
header of my website - or more accurately, customize the wordpress theme so 
that I can put an animated gif next to the header.

I'll include a link in case the moving logo does not work on this forum


content.screencast.com/users/dchristensen777/folders/Default/media/d641cee8-137c-456d-afc1-334e75526254/logo
 GIRL_SHADOW.gif




Cheers   
Donald
0423 102 090   
www.sundialsforlearning.com
   




---
https://lists.uni-koeln.de/mailman/listinfo/sundial




  ---
  https://lists.uni-koeln.de/mailman/listinfo/sundial









---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.2890 / Virus Database: 2637/6024 - Release Date: 01/10/13
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Railways and Sundials

[Roger Bailey]

Wow what a project. I wondered why you were quiet last year but this explains 
it all. Thanks John for sharing it with us.

Regards, Roger 


From: John Carmichael 
Sent: Friday, January 04, 2013 9:37 PM
To: sundial@uni-koeln.de 
Subject: RE: Railways and Sundials


Hello All:

 

Bare with me, this email will eventually relate to sundials (as Roger says, 
everything eventually does.)

 

I sheepishly must admit that I have been unusually quiet on the list for one 
year. Let me explain.

 

It wasn't for lack of interest in all your postings which I have been reading, 
it was because I was so deeply involved in a giant project which consumed all 
my time and undivided attention. It took over my life for one year (and helped 
me to escape the horrible state of world and national affairs.  I literally 
made my own little world and never left town). I have been working non-stop all 
day, every day for thirteen months on this project. Without the encouragement 
and support from my family and friends, it would not have been possible.

 

I have been making sundials for twenty years.  But had a crazy dream festering 
in the back of my head for just as long.  Ever since they were invented in 
Germany in the 1980s, I've wanted to design and build a Garden Railway. They 
can be magical and most satisfying things.  I figured that I'm starting to get 
old and if I waited any longer I physically wouldn't be able to do it.  So I 
bit the bullet and made a big decision to temporally halt my sundial business, 
retool my shop, and make the railroad.

 

Then along came the letter from Gianni Ferrari on Railway Sundials, and it woke 
me up and I realized that sundials do relate to everything. (thanks Roger).  
Well, Gianni's letter also gave me an idea.

 

Many years ago, NASS gave me the Sawyer Dialing Prize which was a beautiful and 
sturdy little brass equatorial dial made by The Great Tony Moss himself.  
Sadly, it has set on my shady workbench, much loved but unused for all these 
years.  I had no sunny window available and no good place outside- until now!  
I thought what a great idea!  I'll use my Sawyer Dialing Prize Sundial as a 
miniature monumental sundial on the railroad.  So I glued it on top of a stone 
pinnacle by the Trolley Station.  Looks great and works just fine.  Thanks Tony 
and Gianni!  Everybody loves it.

 

I'm back at dialing again and have orders.  The break was good, but I'm happy 
to be dialing again.

 

Here is a Flickr set of the new railroad, including the railroad sundial: 
http://www.flickr.com/photos/jlcarmichael/sets/72157632430552837/ 

I didn't have time to write descriptions under each photo, so you'll just have 
to guess what you are looking at.

All aboard!

John

 

 


 

 

 

 

John L. Carmichael

Sundial Sculptures

925 E. Foothills Dr.

Tucson AZ 85718-4716

USA

Tel: 520-6961709

Email: jlcarmich...@comcast.net 

 

My Websites:

(business) Sundial Sculptures: http://www.sundialsculptures.com 

(educational) Chinook Trail Sundial: 
http://advanceassociates.com/Sundials/COSprings/

(educational) Earth  Sky Equatorial Sundial: 
http://advanceassociates.com/Sundials/Earth-Sky_Dial/  

(educational) My Painted Wall Sundial: 
http://www.advanceassociates.com/WallDial 

(educational) Painted Wall Sundials: 
http://advanceassociates.com/WallDial/PWS_Home.html 

(educational) Stained Glass Sundials: http://www.stainedglasssundials.com 

(educational) Sundial Cupolas, Towers  Turrets: 
http://StainedGlassSundials.com/CupolaSundial/index.html 

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Gianni Ferrari
Sent: Saturday, December 01, 2012 4:02 AM
To: LISTA INGLESE
Subject: Rrailways and sundials

 

Maybe someone is interested in the group of monothematic sundials that Italian 
gnomonists Giacomo Bonzani and Guido Dresti have designed on the walls of the 
stations of a small mountain railway (52km)  which connects the town of 
Domodossola (Northern Italy) with nearest Switzerland.
Greetings

Gianni Ferrari 

LInk:

http://lnx.vigezzonews.it/index.php?option=com_contentview=articleid=750:la-valle-dal-tempo-dipintocatid=38:la-valle-dal-tempo-dipintoItemid=62

 

-
Ing. Gianni Ferrari 

Lat.44;38,18.5N
Long. 10;56,05.3E
gfme...@gmail.com

 






---
https://lists.uni-koeln.de/mailman/listinfo/sundial







No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.2805 / Virus Database: 2637/6010 - Release Date: 01/04/13
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Canadian Inauguration

[Roger Bailey]

Hello Tony,

 A Mari Usque ad Mare or From sea to sea is the motto on Canada's official 
Coat of Arms. See http://www.heraldry.ca/misc/coatArmsCanada.htm

You have achieved that A Mari Usque ad Mare status with your sundials, one 
small custom dial with me on the Pacific Coast, Vancouver Island and now one 
large reproduction the Atlantic Coast, Prince Edward Island. This is an 
achievement as Canada spans four and a half time zones from sea to sea. Again 
thanks for the sundial and congratulations! 

NASS has few members in the Maritimes. To my knowledge there are no members in 
PEI and Nova Scotia but three in New Brunswick. Two of those contribute to this 
list from Fredericton about 300 km away from Charlottetown. Alas, I am as far 
away as you are.

Regards, 
Roger Bailey


From: Tony Moss 
Sent: Saturday, October 20, 2012 1:31 AM
To: sundial@uni-koeln.de 
Subject: Canadian Inauguration


Fellow Shadow Watchers,

On Friday 26th October at Holland College on Prince Edward Island in Canada a 
full-size re-production of a sundial made by Heath and Wing of London in 1773 
will be inaugurated.  This 17.4 diameter instrument was the last commercial 
sundial to leave my workshop in 2011.

Inscribed The gift of SAMUEL HOLLAND  Esq. his MAJESTY's Surveyor 
   General of Lands for the Northern District of North
 America to Dartmouth College New Hampshire  

By kind permission of Dartmouth College, the dial, in phosphor bronze, has been 
accurately reproduced but re-delineated to read correctly at its new location.

The time of the inauguration has yet to be announced but will be published on 
the SML as soon as I have been informed of it.  The college authorities would 
welcome the attendance of any dialists from NASS or BSS who might be nearby at 
the time.

How I wish I could be there :-(

Tony Moss






---
https://lists.uni-koeln.de/mailman/listinfo/sundial

---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: BBC iPlayer - Antiques Roadshow.

[Roger Bailey]

Thank you Mike for creating an interesting lesson on heliochronometers.

Thank you, Barry for making this available along the lines of acceptable 
use within the copyright and intellectual property laws. I see the sundial 
list was included as a bcc. I will respect that.


Thank you Steve for pointing out that there are laws on digital copyrights 
that are getting more restrictive. The free internet that we have all 
contributed to is rapidly becoming a restrictive business.


Regards, Roger Bailey


--
From: Steve Lelievre steve.lelievre.can...@gmail.com
Sent: Monday, October 15, 2012 9:02 AM
To: sundial@uni-koeln.de
Subject: Re: BBC iPlayer - Antiques Roadshow.


On 15/10/2012 10:48 AM, brick...@62bricks.com wrote:
Online content that is blocked for certain regions can be viewed using a 
proxy service. There is a simple program called Tunnelbear, available at 
http://tunnelbear.com , that will allow you to view content that is 
restricted to the UK. You just download the program, turn it on and set 
it to UK and sites like BBC iPlayer will function. The service is free 
with a monthly data limit.





Using proxy services is common and completely legal


In the context of Mac's question, the above statement seems overly simple 
to me, and a full answer must depend on the country you live in.


In Canada, using a proxy service is indeed completely legal in itself. 
However, with the Copyright Moderization Act passed back in September it 
becomes a crimal offence to avoid, bypass, remove, deactivate or impair 
[a] technological protection measure unless it is done with the authority 
of the copyright owner where a technological protection measure is 
defined as any effective technology, device or component that, in the 
ordinary course of its operation [...] controls access to a work. The new 
law is still waiting for Royal Assent but this is expected soon.


In its ordinary course of operation the iPlayer prevents access for non-UK 
viewing. This control is in place specifically for copyright reasons so, 
to my way of thinking, in Canada use of a proxy could perhaps be contrued 
as an attempt to circumvent the protection measure. An analogy might be 
that although it's OK to posess a screwdriver, it is illegal in Canada to 
use that screwdriver to remove a neighbour's doorlock to get in order to 
use the pool while the neighbour is on vacation.


I concede however, that I have no legal training, and of course there's no 
Case Law in place yet to guide us on how the courts would actually view 
the practice.


Steve








On 15.10.2012 06:05, Mac Oglesby wrote:

Alas! I get a message saying BBC iPlayer programmes are available to
play in the UK only,

Any alternatives which might let those of us not in the UK see Mike?

Best wishes,

Mac Oglesby



---
https://lists.uni-koeln.de/mailman/listinfo/sundial


---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Sundial Elferberg (Neustift im Stubaital)

[Roger Bailey]

Great photos. I didn't notice the first one was a 360° panorama at first. 
Thanks.

Roger Bailey


From: Josef Pastor 
Sent: Sunday, October 07, 2012 11:18 AM
To: 'Sonnenuhrliste Uni Köln' 
Subject: Sundial Elferberg (Neustift im Stubaital)


Dear Dialists,



the Panorama Community published some photographs (even panoramic photos at 
night) of a sundial in Austria. Enjoy it!



http://www.panorama-community.net/wbb/index.php?page=ThreadthreadID=7981 

Best regards 

Josef Pastor








---
https://lists.uni-koeln.de/mailman/listinfo/sundial

---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Sundials in playgrounds - at last, the tide is turning !

[Roger Bailey]

Yes Jack, it is classic bumf, appropriately scored by Glass.

Regards, Roger bailey

--
From: Jack Aubert j...@chezaubert.net
Sent: Saturday, September 15, 2012 8:07 PM
To: sundial@uni-koeln.de
Subject: RE: Sundials in playgrounds - at last, the tide is turning !


It is interesting to note how the Health and Safety Executive was able to
take a thought that could be succinctly expressed in two sentences and 
turn
it into fifteen numbered paragraphs pages with two footnotes by spinning 
out
variations and permutations on a simple theme.  If it were set to music 
the

composer would have to be Philip Glass

Jack Aubert


-Original Message-
From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Martina
Addiscott
Sent: Friday, September 14, 2012 6:37 AM
To: sundial@uni-koeln.de
Subject: Sundials in playgrounds - at last, the tide is turning !


Following-on from previous correspondence, it actually seems that the UK
Health and Safety Executive have realised just how ridiculous it is for
schools to be 'banning' any outdoor activities - simply because there was 
a
small element of risk involved, which might ultimately result in some 
legal

action.

They have now issued a statement (see the attached PDF file), in an 
attempt

to clarify this unfortunate situation - which was causing Analemmatic
playground layouts to be discouraged, both here in the UK and in other
countries such as Australia.

This might be of use to list-member Donald Christensen - whom I know is
active in this area, within the Australian system.


So it looks like the tide might be turning, back to a more 'sensible'
approach to evaluating levels of risk to children, and as well as the
attached file there is further information at
http://charityemail.org.uk/LJV-YM4F-39UDPL-DE93G-0/c.aspx


Sincerely,

Martina Addiscott.



--

--
This message has been scanned for viruses and dangerous content by
MailScanner, and is believed to be clean.




--
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.

---
https://lists.uni-koeln.de/mailman/listinfo/sundial


---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: analemmatic sundial on a slope

[Roger Bailey]

Hello Donald,

My initial impression is that you have captured the essence of analemmatic 
sundials. They are a a projection straight down of the equatorial disc for the 
hour ellipse and the active portion of the polar gnomon for the zodiac line. 
Normally the projection is onto a horizontal plane, but it could be a sloping 
plane as well so your solution follows the correct logic.

Regards, 
Roger Bailey. 
N 48.6, W 123.4



From: Donald Christensen 
Sent: Friday, September 07, 2012 7:12 PM
To: sundial@uni-koeln.de 
Subject: analemmatic sundial on a slope


Will an analemmatic sundial work on a slope?




I've designed a sundial on a slope but I'm not sure if it will work.




http://content.screencast.com/users/dchristensen777/folders/Default/media/0a769c4b-d61c-4f5d-b187-5b74dbc56e07/1.jpg




This is a pic of an equatorial dial. I have projected the lines down to draw an 
analemmatic sundial for a horizontal surface. The sunlight strikes the blue 
gnomen on the equatorial dial. Where it hits the gnomen, I project it down 
(red) to draw the month line. The shadow then strikes the 1pm and I project 
that down as well.




http://content.screencast.com/users/dchristensen777/folders/Default/media/6abf010e-8416-41a3-ba75-f69f63d0109f/2.JPG





This is an analemmatic sundial designed on a horizontal surface. I have 
projected all hour and month points down to where they intersect on the gray 
slope.







http://content.screencast.com/users/dchristensen777/folders/Default/media/5354cc54-f058-4854-bb3a-844a9b8fa89f/3.JPG





This is the analemmatic sundial designed for a slope.




I'm unsure this will work. I'm confident that I projected the lines correctly. 
A person that stands on the month line will be standing upright. They won't be 
perpendicular to the ground. Of course a gnomen that is perpendicular to the 
slope won't work. However I'm wondering if a vertical gnomen will work

Cheers
Donald
0423 102 090


This e-mail is privileged and confidential. If you are not the intended 
recipient please delete the message and notify the sender. Un-authorized use of 
this email is subject to penalty of law.
So there!






---
https://lists.uni-koeln.de/mailman/listinfo/sundial

---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: What is the deal with this dial?

[Roger Bailey]

Hi Bill and all,

Could it be an am pm thing. I see the numerals after noon as AI and AII. A P 
for post  would be more appropriate. In Latin A=ante =before but perhaps now 
A=after as in afternoon in globalspeak. Perhaps we need a Lingua Franca like 
Latin or Esperanto or English.

Regards, Roger


From: Bill Gottesman 
Sent: Tuesday, September 04, 2012 7:16 PM
To: Sundials List 
Subject: What is the deal with this dial?


Hello All, 


A friend returned from Italy with this photo (94kb) of a vertical dial.  Some 
of the numbers are hard to read, but near noon they seem to run X, XI, XII, V, 
IV, III.  Can someone explain this to me?  I do not know wall declination or 
the angle of the gnomon.


-Bill





---
https://lists.uni-koeln.de/mailman/listinfo/sundial

---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: IMAGES APLENTY

[Roger Bailey]

Yes, Google Images offers many hits, mostly irrelevant. Frank King BSS 
Cambridge brings up only one image. Ditto Frank King sundials. Roger Bailey 
sundials brings up 10 legitimate hits on my computer, the first ten of many 
irrelevant hits. Is this because Google searching on my computer knows me?


Regards, Roger Bailey

--
From: Frank King frank.k...@cl.cam.ac.uk
Sent: Monday, August 27, 2012 10:02 AM
To: Tony Moss tonylindi...@talktalk.net
Cc: sundial@uni-koeln.de
Subject: Re: IMAGES APLENTY


Dear Tony,

Google Images indeed represents a splendid
resource and you can find lots of good pics
of sundials and, if you wish, pictures of
noted celebrities too.

Try entering Tony Moss and you will see
that you have more impersonators than Elvis!
Still, the real thing is there around image
Number 20 and again at around Number 70.

Just keep going and you will come to the
sundials too!  You will find pieces about
you and your dials in Polish and French,
but you know all that already!  I really
like the WizardWand sun-substitute.

Gee, what it is to have such CyberFame!

All the best

Frank

---
https://lists.uni-koeln.de/mailman/listinfo/sundial


---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: sundials in schools

[Roger Bailey]

Well done. This is a useful instruction website.

Regards, Roger Bailey 


From: Donald Christensen 
Sent: Sunday, August 12, 2012 10:14 PM
To: sundial@uni-koeln.de 
Subject: sundials in schools


My website is finally done

It's about putting in analemmatic sundials in schools.

http://www.youtube.com/watch?v=SoW-Kl_kaxw


http://www.sundialsforlearning.com/



Cheers
Donald
0423 102 090


This e-mail is privileged and confidential. If you are not the intended 
recipient please delete the message and notify the sender. Un-authorized use of 
this email is subject to penalty of law.
So there!






---
https://lists.uni-koeln.de/mailman/listinfo/sundial

---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Sundial on Mars

[Roger Bailey]

This is the Mars dial designed by Woody Sullivan at the University of 
Washington. He gave a short update on the design at the NASS Conference in 
Seattle last year. See 
http://www.sundials.org/attachments/article/174/2011%20NASS%20Conference%20Seattle.pdf 
for a retrospective on the conference but very little on the dial.


Yes, the sundial is based on a colour comparator and the orientation of the 
dial changes when the rover moves. The hour lines lines are added by NASA 
back on Earth. The original design is described on Woody's website, more 
specifically in the following article. See 
http://www.astro.washington.edu/users/woody/MarsDial.Plan_Rept.Jan04.pdf .


Regards, Roger Bailey

--
From: da...@davidbrownsundials.com
Sent: Friday, August 10, 2012 2:03 AM
To: sund...@rrz.uni-koeln.de
Subject: Sundial on Mars


Dear Diallists,
I thought you might find this particularly interesting, sent to me by my
USA-based son.

http://mars.jpl.nasa.gov/msl/multimedia/interactives/learncuriosity/index-2.html
then click on the arrow until you get to the description of the 'Back'
Click on the sundial (near the top/middle)

Also:

http://www.pcworld.com/article/260579/mars_rover_curiosity_a_complete_guide_to_tagging_along_online.html



In particular:
https://twitter.com/marscuriosity
https://twitter.com/sarcasticrover  (unofficial I'm guessing :)

David Brown
Somerton, Somerset, UK

---
https://lists.uni-koeln.de/mailman/listinfo/sundial


---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Everything I Need to Know....

[Roger Bailey]

I have often said Everything I need to know I learned from sundials.  The 
nerd stuff is easy to understand in this context, the ability to cast a sundial 
of ant type for any location and orientation. But it goes well beyond that, 
into the cultural aspects, answering not just the how questions but why. I 
am now working with Rafael Soler on the solar phenomenon with the cathedral in 
Palma Mallorca. Here there are a couple of interesting solar displays due to 
the orientation of the rose windows in this cathedral. One is on the winter 
solstice, the other when the solar declination is about 17°, 2nd February, 2/2, 
and 11 Nov 11/11. These happen to be the feast days of Candelaria (Candlemas) 
and St Martin (Martinmas). These are significant dates  in various Christian 
traditions but they go way back in many cultures. Candlemas is half way from 
the winter solstice to the equinox, a significant calendar event. Martinmas in 
many cultures is thanksgiving day, a day to celebrate the harvest and  
slaughter the pigs in preparation for winter. The 11th minute of the 11th hour 
of the 11th month is also the timing of the armistice that ended WW1, now 
Remembrance or Veterans day in many countries. The sun rules the seasons and 
our cultural norms. Some are so deeply engrained that they are hard to 
acknowledge. Sundial can provide a window.

For specific information stay tuned to the presentation at the NASS Conference 
on The Cathedral of Light or wait for Rafael Soler's article, The Phenomenon 
of Sunlight on Rose Windows in a future Compendium. These cover the nerd stuff 
but really cannot answer why. 

Regards,

Roger Bailey---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: a way to determine the period of insolation of a wall, using an analemmatic sundial

[Roger Bailey]

Hello Frank,

This is an interesting example but I don't quite agree with your conclusion. 
I estimate the south wall receives 13:20 hours and the north side only 
10:40. To draw the analemmatic sundial with Lambert Circles in green and 
seasonal marker azimuth lines in blue, I use the DeltaCad NASS macro 
attached. Fer de Vries wrote the original. I hacked it to include seasonal 
markers as a separate layer. This example also shows that the seasonal 
marker concept fails at high latitudes. The rise and set azimuth lines no 
longer converge.


Roger Bailey

--
From: Frank King frank.k...@cl.cam.ac.uk
Sent: Monday, July 02, 2012 7:37 AM
To: 'Willy Leenders' willy.leend...@telenet.be; 'Sundial sundiallist' 
sundial@uni-koeln.de; Frank King frank.k...@cl.cam.ac.uk
Subject: Re: a way to determine the period of insolation of a wall, using an 
analemmatic sundial



Dear Willy,

I much enjoyed looking at your diagrams on:

 http://www.wijzerweb.be/analemmatischengels.html

Now consider the following special case...

 1. Use the latitude of the Arctic Circle

 2. Take a Direct NORTH-facing vertical wall

 3. Take the day of the Summer Solstice

 4. Assuming a clear sky, for how many hours can
sunlight fall on the north face of the wall?

This is the theoretical maximum sunlight that a
(single-sided) vertical wall can receive in a day.
The south side doesn't get so much sun!

Your diagram works very well, though some readers
may find the Lambert Circle a little surprising in
this special case :-)

Frank King
Cambridge, U.K.

---
https://lists.uni-koeln.de/mailman/listinfo/sundial


hor_analem3SM.bas
Description: Binary data
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: a way to determine the period of insolation of a wall, using an analemmatic sundial

[Roger Bailey]

The original was too large for the size filter. Attached is a small version as 
a GIF. Regards, Roger


From: Roger Bailey 
Sent: Monday, July 02, 2012 9:09 AM
To: 'Willy Leenders' ; 'Sundial sundiallist' ; Frank King 
Subject: Re: a way to determine the period of insolation of a wall, using an 
analemmatic sundial


Here is a copy of the sketch for those without DeltaCAD. Green are the Lambert 
Circles for various dates. Blue are the azimuth lines for sunrise and set. The 
math fails when sunrise and set is at 12, due north, on the summer solstice. 
The wall parallel is the black line through the date point. This wall line 
crosses the sundial ellipse when the sun is due east and west as the wall faces 
due north and south.  

Regards, Roger





--
From: Frank King frank.k...@cl.cam.ac.uk
Sent: Monday, July 02, 2012 7:37 AM
To: 'Willy Leenders' willy.leend...@telenet.be; 'Sundial sundiallist' 
sundial@uni-koeln.de; Frank King frank.k...@cl.cam.ac.uk
Subject: Re: a way to determine the period of insolation of a wall, using an 
analemmatic sundial

 Dear Willy,
 
 I much enjoyed looking at your diagrams on:
 
  http://www.wijzerweb.be/analemmatischengels.html
 
 Now consider the following special case...
 
  1. Use the latitude of the Arctic Circle
 
  2. Take a Direct NORTH-facing vertical wall
 
  3. Take the day of the Summer Solstice
 
  4. Assuming a clear sky, for how many hours can
 sunlight fall on the north face of the wall?
 
 This is the theoretical maximum sunlight that a
 (single-sided) vertical wall can receive in a day.
 The south side doesn't get so much sun!
 
 Your diagram works very well, though some readers
 may find the Lambert Circle a little surprising in
 this special case :-)
 
 Frank King
 Cambridge, U.K.
 
 ---
 https://lists.uni-koeln.de/mailman/listinfo/sundial
attachment: Lambert SM.gif---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Fw: a way to determine the period of insolation of a wall, using an analemmatic sundial

[Roger Bailey]

I am now in full agreement that the north side of the wall gets more 
sunshine. When the sun is to the north side of the wall, the hours indicated 
by the shadow are read on the south side of the hour ellipse.


Regards, Roger

--
From: Roger Bailey rtbai...@telus.net
Sent: Monday, July 02, 2012 8:56 AM
To: 'Willy Leenders' willy.leend...@telenet.be; 'Sundial sundiallist' 
sundial@uni-koeln.de; Frank King frank.k...@cl.cam.ac.uk
Subject: Re: a way to determine the period of insolation of a wall,using an 
analemmatic sundial



Hello Frank,

This is an interesting example but I don't quite agree with your 
conclusion.

I estimate the south wall receives 13:20 hours and the north side only
10:40. To draw the analemmatic sundial with Lambert Circles in green and
seasonal marker azimuth lines in blue, I use the DeltaCad NASS macro
attached. Fer de Vries wrote the original. I hacked it to include seasonal
markers as a separate layer. This example also shows that the seasonal
marker concept fails at high latitudes. The rise and set azimuth lines no
longer converge.

Roger Bailey

--
From: Frank King frank.k...@cl.cam.ac.uk
Sent: Monday, July 02, 2012 7:37 AM
To: 'Willy Leenders' willy.leend...@telenet.be; 'Sundial 
sundiallist'

sundial@uni-koeln.de; Frank King frank.k...@cl.cam.ac.uk
Subject: Re: a way to determine the period of insolation of a wall, using 
an

analemmatic sundial


Dear Willy,

I much enjoyed looking at your diagrams on:

 http://www.wijzerweb.be/analemmatischengels.html

Now consider the following special case...

 1. Use the latitude of the Arctic Circle

 2. Take a Direct NORTH-facing vertical wall

 3. Take the day of the Summer Solstice

 4. Assuming a clear sky, for how many hours can
sunlight fall on the north face of the wall?

This is the theoretical maximum sunlight that a
(single-sided) vertical wall can receive in a day.
The south side doesn't get so much sun!

Your diagram works very well, though some readers
may find the Lambert Circle a little surprising in
this special case :-)

Frank King
Cambridge, U.K.

---
https://lists.uni-koeln.de/mailman/listinfo/sundial






---
https://lists.uni-koeln.de/mailman/listinfo/sundial



---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Sundial found in Jamestown excavation

[Roger Bailey]

I checked an article in Le Gnomoniste on the discovery of a 17th century 
sundial in Montreal. The analysis also used a Serle Ruler and references NASS 
and Fred Sawyer's article. See 
http://cadrans_solaires.scg.ulaval.ca/v08-08-04/pdf/XVI-2.pdf . The Serle is 
shown in figure 3 page 9. The analysis indicates a vertical sundial declining 2 
to 3 degrees, designed and crafted in Montreal in the 17th century but not 
before Jamestown. 

Now where did I put my Serle Ruler?

Regards 



From: J. Tallman 
Sent: Wednesday, June 27, 2012 12:27 PM
To: fwsaw...@aya.yale.edu 
Cc: Sundial Mailing List 
Subject: Re: Sundial found in Jamestown excavation


This is great, thanks Fred.

After seeing this and also seeing so many really old dials in the BSS Bulletin 
it makes me wonder about a question that might make an interesting thread...

What is the oldest dial in North America? Are there any unique ways that old 
dials here in the New World differ from their European counterparts?


Best,

Jim Tallman
www.spectrasundial.com
www.artisanindustrials.com
jtall...@artisanindustrials.com
513-253-5497

Fred Sawyer fwsaw...@gmail.com wrote:

An exciting find in the Jamestown excavation - a 17th century diptych dial.

See the article at: 

http://popular-archaeology.com/issue/june-2012/article/archaeologists-unearth-rare-17th-century-find-at-jamestown-excavations

Be sure to view the video that shows the actual uncovering of the dial and the 
reverse engineering that determined the latitude for which it was made.  Note 
that the dialing scale the archeologist is using is a NASS scale I provided to 
members many years ago at the first NASS conference.  (BTW if you haven't yet 
sent in your registration for this year's conference in Asheville NC, please do 
it soon!)  I believe the instructions he was using came from the Compendium 
article by Steve Woodbury.

Fred Sawyer









---
https://lists.uni-koeln.de/mailman/listinfo/sundial

---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Calculating azimuth of sunrise and sunset from present back 25, 000 years

[Roger Bailey]

Hello David,

I recognized my error in the middle of the night, long after pressing the 
send button. 150 m is still locally significant. Over millions of years 
these forces move mountains and continents.


Regards, Roger

--
From: David Patte ? dpa...@relativedata.com
Sent: Sunday, June 24, 2012 9:26 PM
To: sundial@uni-koeln.de
Subject: Re: Calculating azimuth of sunrise and sunset from present back 
25,000 years



If I'm not mistaken:

25,000 x 6 mm = 150,000 mm = 150m, not 1500m

Did you mean cm?


On 2012-06-25 0:11, Roger Bailey wrote:
At this time I am moving 6 mm per year towards the east, as determined by 
precise GPS and laser surveys. Over 25,000 years this movement is a mile, 
1.5 km and a lot of earthquakes.



--

---
https://lists.uni-koeln.de/mailman/listinfo/sundial



---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: The most exact sundial of the world In Samedan!

[Roger Bailey]

Thanks Fabio,

The link you provided Sine Sole Sileo has a link to a pdf that gives 
instructions in several languages including English. Here is a direct link:
http://objects.estm.xiag.ch/images/Bergbahnen/Bedienungsanleitung_Sonnenuhr_Balken.pdf

Regards, Roger Bailey


From: Fabio nonvedolora 
Sent: Sunday, June 24, 2012 11:09 AM
To: Sundial Mailingliste 
Subject: Re: The most exact sundial of the world  In Samedan!


On Sundial Atlas there is the card of this sundial with 4 pdf files attached, 
one of them with technical info. All of them are in german.
www.sundialatlas.eu/atlas.php?so=CH220

ciao Fabio

Fabio Savian
fabio.sav...@nonvedolora.it
Paderno Dugnano, Milano, Italy
45° 34' 10'' N, 9° 10' 9'' E, GMT+1 (DST +2)

From: Reinhold Kriegler 
Sent: Sunday, June 24, 2012 4:39 PM
To: Sundial Mailingliste 
Subject: The most exact sundial of the world  In Samedan!

Dear friends! Have a look to Switzerland!

Genaueste Sonnenuhr der Welt steht im Engadin 
Auf Muottas Muragl auf 2456 Meter über Meer ist am Donnerstag die genaueste 
Sonnenuhr der Welt eingeweiht worden.

  a.. 
http://www.bote.ch/vermischtes/genaueste-sonnenuhr-der-welt-steht-im-engadin 

  Quelle: suedostschweiz.ch 
  b.. Datum: 22.06.2012, 17:00 Uhr 
  c.. Webcode: 39872 

O I “love” the superlatives in connection with sundials!! :-)

So far this one I did not know: “The most exact sundial of the world!”

 
Best regards

Reinhold Kriegler

 

 

* ** ***  * ** ***

Reinhold R. Kriegler

Lat. 53° 6' 52,6 Nord; Long. 8° 53' 52,3 Ost; 48 m ü. N.N. 
GMT +1 (DST +2)  www.ta-dip.de

http://www.ta-dip.de/dies-und-das/r-e-i-n-h-o-l-d.html 
http://www.ta-dip.de/salon-der-astronomen/bewohner-des-salons-der-astronomen.html

 




---
https://lists.uni-koeln.de/mailman/listinfo/sundial







---
https://lists.uni-koeln.de/mailman/listinfo/sundial

---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Calculating azimuth of sunrise and sunset from present back 25, 000 years

[Roger Bailey]

Hello Frank and all,

You raise an interesting point . At first I thought that we should not 
confuse human time, 25,000 years with geological time, 25 million years. 
Then I reconsidered. We tend to think in terms of the Rock of Ages, solid 
enduring and unmoving, not considering the geological record. The sea level 
changes in the latest glacial cycle is well within 25,000 years. Isostatic 
rise continues here as glaciers continue to recede. I see the evidence daily 
of the glacial cycles and sea level changes and know there was over 300 m of 
ice covering my location in the last 25,000 years. But land movement? 
Perhaps.


I live on the west coast of North America, in the shadow of the Cascadia 
Fault. This will be the site of a M9+ megathrust earthquake and tsunami like 
the recent ones in Japan and Indonesia at any time. The question is not if 
but when for a rupture from mid British Columbia to mid California. The last 
one was in 1701 according to records in Japan on destruction in Kyoto etc. 
and  local aboriginal oral histories. There were no white settlers here at 
the time, only 300 years ago. The near term geological records show 17 
similar large megathrust earthquakes along the Cascadia Fault occurring 
every 300 to 500 years. At this time I am moving 6 mm per year towards the 
east, as determined by precise GPS and laser surveys. Over 25,000 years this 
movement is a mile, 1.5 km and a lot of earthquakes.  Does this affect the 
alignment of stone fences? The earthquakes may knock them down but the 
motion here is translation at 61° east not rotation. If Australia is like 
here, the alignment of stone fences may still tell us about where we are in 
terms of the development of human intelligence


Everything I need to know I am learning from sundials.

For further information I recommend Cascadia's Fault by Jerry Thompson. 
ISBN 978-1-554468-466-3. It is a wake up call.


Regards,
Roger Bailey
N 48.66, W 123.40
Sidney by the Sea, BC

--
From: Frank King frank.k...@cl.cam.ac.uk
Sent: Saturday, June 23, 2012 11:37 PM
To: Brad Lufkin bradley.luf...@gmail.com
Cc: Sundial Mailing List sundial@uni-koeln.de
Subject: Re: Calculating azimuth of sunrise and sunset from present back 
25,000 years



Dear Brad et al,

I have enjoyed this thread and you ask one
crucial question which is more difficult to
answer than many might think...

  In the meantime, could you tell me what
  the latitude of the place of interest is?

This question is flawed.  The final word should
not be is but was!

In 25,000 years there will have been significant
tectonic plate movement.  Unfortunately, this
movement is not just in translation but also
rotation.  The objects whose alignment John
Pickard is interested in are no longer where
they were and no longer aligned as they were.

You probably also need to allow for changes in
isostasy too, the ground will undoubtedly have
heaved or dipped over time.

Real life always asks tough questions!

Frank King
Cambridge, U.K.

---
https://lists.uni-koeln.de/mailman/listinfo/sundial


---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Transit of Venus, 2012- an invitation to have a look!

[Roger Bailey]

Thanks Reinhold,

I was fortunate to be able to observe a couple of hours of the transit from my 
home, Sidney by the Sea, BC, 48.6 N, 123.5 W. It was cloudy most of the day so 
I made no preparations but after 4 pm PDST, the sky cleared. I tried a pinhole 
projection in a box but the image was too small and fuzzy. I then rushed around 
to get binoculars, make a bracket and mount the binoculars on a tripod facing 
the sun. The projected image of the sun was about 30 mm across on the white 
board about 70 cm from the binoculars. Venus was a surprisingly large dot in 
the lower right side of the image. This moved up and to the right as the 
transit proceeded. A number of sunspots were also clearly visible. I was able 
to observe it with neighbours, their kids and grandkids for a couple of hours. 
It was an interesting experience.

The location and direction of the transit was not what I expected from the 
information on the web. Those pictures show the sun with its north pole up I 
had no reference point for solar north. Perhaps the difference was due to my 
latitude. The binoculars did not invert the image the way telescopes do. I 
could not observe the start due to clouds of the finish due to sunset. The only 
pictures I took just show the simple, safe and effective setup. The projected 
image lacked enough contrast to photograph well.

Regards, Roger Bailey

From: Reinhold Kriegler 
Sent: Wednesday, June 06, 2012 2:58 AM
To: Sundial Mailingliste 
Subject: Transit of Venus, 2012- an invitation to have a look!


Dear friends,

 

I would like to invite you to have a look at this most beautiful 
Venust-transit-2012-story by my friend Mohamad Soltanolkotabi from Isfahan/ 
Iran!



 

With best wishes!

Reinhold Kriegler



And also a friendly invitation – afterwards also to visit my little link:
http://www.ta-dip.de/dies-und-das/venustransite-2004-2012-2117.html 





* ** ***  * ** ***

Reinhold R. Kriegler

Lat. 53° 6' 52,6 Nord; Long. 8° 53' 52,3 Ost; 48 m ü. N.N.  GMT +1 (DST +2)   
www.ta-dip.de

http://de.youtube.com/watch?v=XyCoJHwzzjUfmt=18

http://www.ta-dip.de/dies-und-das/r-e-i-n-h-o-l-d.html
http://www.ta-dip.de/dies-und-das.html

-Ursprüngliche Nachricht-
Von: msoltanolkot...@gmail.com [mailto:msoltanolkot...@gmail.com] Im Auftrag 
von mohamad soltanolkotabi
Gesendet: Mittwoch, 6. Juni 2012 10:58
An: undisclosed-recipients:
Betreff: Transit of Venus, 2012

 

گالری عکس گذر ناهید، 1391
MSOL Venus transit, 2012 photo gallery










---
https://lists.uni-koeln.de/mailman/listinfo/sundial

image001.jpg---
https://lists.uni-koeln.de/mailman/listinfo/sundial