the reader :-)
>
> Frank King
> Cambridge, UK
>
>
>
>
> --
>
> Subject: Digest Footer
>
> ___
> sundial mailing list
> sundial@uni-koeln.de
> https://lists.uni-koeln.de/mailman/list
David doesn't seem to have replied, as far as I can see, so perhaps I can
rephrase his point.
The diagram assumes all the hour lines converge on a point, so it assumes a
thin gnomon with a knife-edge or a thin rod or wire (as used by John
Carmichael). But many dials have a thick gnomon with two
By a map of the earth do you mean a map that shows continents and so on? If
so, do you want Australia to be visible?
The grid you are after is extremely simple. Each longitude line is an ellipse,
with major axis equal to the diameter of the overall map and minor axis equal
to this multiplied by
An armillary sphere can be used in either hemisphere. The only issue is that
the hour numbers, if written with their base lines along the equatorial ring,
will be upside down, but you could provide numbers facing both ways, one set
either side of the centre of the hour band. Or, you could turn
On Thursday, June 23, 2011 9:33 AM, Frank Kingfrank.k...@cl.cam.ac.uk,
commenting on Kevin Karney's ke...@karney.com posting, said
...the master of all mechanical EoT
generators must be the device in the
Strassburg cathedral clock.
You overlook the mechanism in the
Jens Olsen World Clock
When I need to drill holes at an odd angle (into stone or an immovable object)
I have made a drill guide in hard wood or composite such as worktop laminate. I
clamp the laminate firrmly at the required angle on my drill press and drill a
hole in it. To start a hole at a shallow angle, you can
Hi Brent,
Everywhere in the world, the sun rises due East on the equinoxes (March 20th
and September 23rd approximately).
Everywhere in the world, the sun rises in the North East between those
dates, such as today. (Ignoring the polar regions.)
May I suggest you get hold of a globe, stick pins in
- Original Message -
From: Frank King frank.k...@cl.cam.ac.uk
To: Reinhold Kriegler reinhold.krieg...@gmx.de
Cc: sund...@rrz.uni-koeln.de
Sent: Sunday, March 27, 2011 12:20 PM
Subject: Re: AW: Year-round day saving time
Dear Reinhold,
snip
Oh. One more thing. Mike says...
If we
Dear Frank, Willy et al,
Surely the Dutch word zonnewijzer is similar to the English word waywiser,
which is a device used to measure distances along roads. The derivation,
according to the Shorter OED, is from the German wegweiser, compounded from
weg=way and weiser, from weisen=to show, being an
can understand, but I'm surprised it works for fish. Perhaps tuna
never dive too deep.
Chris Lusby Taylor
- Original Message -
From: Brooke Clarke brooke95...@att.net
To: 'sundial' sund...@rrz.uni-koeln.de
Sent: Tuesday, October 12, 2010 5:54 PM
Subject: Light Based Geolocation
Hi
Hi Tom and Brent,
Yes, I agree. Brent is correct that the angle of elevation of the stick is
the co-latitude. The confusion arose, I guess, because the angle of a
normal gnomon is exactly 90 degrees different, so its elevation is the
latitude.
So the statement The sun is due South at solar Noon
Hi Willy,
No, but I bet it looks like this.
Best wishes
Chris
- Original Message -
From: Willy Leenders
To: Sundial sundiallist
Sent: Thursday, April 08, 2010 7:22 PM
Subject: Drawing that belongs to the theorem of Emerson
This is the address where you can find Dialing or
I've just put BBC2 on. They are showing a programme about learning
stonemasonry. The learners will have to make a sundial. The programme is on
right now 9pm to 10pm.
I expect it will be available on the BBC Web site via the iPlayer for one
week.
Must get back to it
Bye
Chris
Utterly brilliant!
Chris
51.4N 1.3W
GMT for another week
- Original Message -
From: Fabio Savian
To: sundial@uni-koeln.de
Sent: Thursday, March 18, 2010 3:21 PM
Subject: Re: DST Misconceptions
...last year I solved the problem of DST at my home; now I've Delight
wouldn't put a wristwatch movement
inside the case instead of the sundial escapes me.
Regards
Chris
- Original Message -
From: Edley McKnight
To: Chris Lusby Taylor ; sund...@rrz.uni-koeln.de ;
patrick_pow...@compuserve.com
Sent: Tuesday, March 09, 2010 5:16 AM
Subject: Re
Hi Peter, Patrick et al,
I've had a brief look at the patent which, by the way, dates from 1953.
It is, as you supposed, an azimuth dial. The two shadow-casting strings, f, are
horizontal, one above the other. The ring, d, must be turned until their
shadows coincide, in other words when they
) to allow daily adjustment to show mean
time, zone time, daylight saving time,
I hope this helps
Happy New Year
Chris Lusby Taylor
51.4N 1.3W
- Original Message -
From: Edley McKnight
To: sundial
Sent: Tuesday, January 05, 2010 5:14 PM
Subject: Quick Bifilar
Dear
the exhibits are indoors and it nearly always rains and a Newbury
Meeting where the exhibits are outdoors and on which the sun always shines.
Coincidence?
Chris Lusby Taylor
- Original Message -
From: Frank King frank.k...@cl.cam.ac.uk
To: j...@chezaubert.net
Cc: 'Sundial' sund...@rrz.uni
Wow, what's going on here! Is it really December in Colorado? Can you visit the
future just by standing on an analemma?
Chris
- Original Message -
From: John Carmichael
To: 'Tom Laidlaw'
Cc: sundial@uni-koeln.de
Sent: Wednesday, November 11, 2009 11:52 PM
Subject: RE:
Thanks for the photo Patrick. Has anyone told the zoo that the sundial has been
installed back-to-front?The globe should be turned around 180 degrees, and
positioned north, not south, of the centre of the base. As it is, it's totally
useless.
By the way, the base could have been inscribed with
- Original Message -
From: Frank King frank.k...@cl.cam.ac.uk
To: Roger Bailey rtbai...@telus.net
Cc: sundial@uni-koeln.de
Sent: Sunday, August 09, 2009 12:36 PM
Subject: Re: Sorry but.Square Roots.Shatir Sundial
Dear Roger,
Thank you for pointing the list at this
YouTube
, or email it privately.
Chris Lusby Taylor
51.4N 1.3W
- Original Message -
From: Tom Laidlaw
To: sundial@uni-koeln.de
Sent: Friday, July 24, 2009 8:10 AM
Subject: analemma on armillary sundial
Hi there,
At Clark College in Vancouver, WA there is an armillary sundial
Pretty? It's utterly gorgeous. As is the astronomer with his telescope. Why
don't we have such paintings in this country (England)?
But wait a second, John. I thought you invented the ball and chain. Didn't you
even patent it?
Best wishes
Confused
51.4N 1.3W
- Original Message -
Hi Ken,
The situation may be better in the USA, but here in the UK the main problem is
that practically all garden centre horizontals I've seen (I try to avoid them)
are made for a much lower latitude than our 50 to 58 degrees.
My advice to people asking this question has been to go for an
they are all, in truth, the
same colour but just look different in the photo.
Chris Lusby Taylor
51.4N 1.3W
- Original Message -
From: Peter Mayer peter.ma...@adelaide.edu.au
To: J. Tallman jtall...@artisanindustrials.com
Cc: Sundial Mailing List sund...@rrz.uni-koeln.de
Sent: Wednesday
Dear Roger,
Thank you for creating this diagram. I'm sure this confirms that the hour
lines on the bottom half of the ring are correct. The upper half of the ring
seems to have equally-spaced lines. To my mind this spoils the symmetry, but
it does not interfere with the functionality of the
Greetings Frank,
I'm sure you're right. This applies to all vertical dials, direct south or
declining by an angle no greater than the maximum angle by which sunrise
differs from due east. The sun only shines on the dial when it is both above
the horizon and in front of the dial plane. The earliest
Dear Frans et al
It takes only two lines of elementary geometry to prove something that you
find so counter-intuitive that you ask for an explanation! That's no
reflection on you, just the beauty of elementary geometry.
I'll attempt an explanation:
Imagine that the ray of light from the sun
Hi David,
We're all getting old, so I may be as wrong as you, but I trust we're both
correct in thinking that the sun is indeed on the meridian around 2pm in France
in the summer. No wonder they manage such lovely long evenings. (Oops,
shouldn't have said that. I mean, no wonder their view of
Hi Alex,
You've gone slightly wrong, I think. On Hendrik's diagrams R is the total
length of the rod or disk from the fixed point to the gnomon. You say you want
this to be 12cm. So R=12cm. This is made up of C, the distance between the
sliders, and D, from the East-West slider to the gnomon.
as how to get the
sundial correctly aligned north-south or what materials and finishes are most
suitable, as well as design issues such as how thick the gnomon should be or
problems/opportunities caused by being in the tropics.
Good luck
Chris Lusby Taylor
51.4N 1.3W
- Original Message
the
time scale. To adjust for a different latitude, you'd have to make the lengths
C and D adjustable. That seems quite feasible to me, though perhaps a bit
fiddly.
Good luck with realising this fascinating dial
Chris Lusby Taylor
51.4N 1.3W
- Original Message -
From: Alex Ware
Hi John,
There used to be someone who made sundials with gnomons that might have been
very suitable, but he seems more interested in stained glass and painted wall
sundials these days ;-)
Why not use a tensioned wire or rod? I'm thinking of sailing yacht rigging,
which may not be perfectly
Hi Keith,
If you know the sun's altitude (Alt) and azimuth (Az), then the angle
of the shadow from vertical is theta where
tan(theta)=sin(Az)/tan(Alt)
I hope the sun shines on your event.
Chris
- Original Message -
From: Keith E. Brandt, WD9GET [EMAIL PROTECTED]
To: sundial [EMAIL
interested, I can post design ideas.
Chris Lusby Taylor
51.4N, 1.3W
- Original Message -
From: Alex Botkin
To: sundial@uni-koeln.de
Sent: Monday, September 29, 2008 3:37 AM
Subject: Temporary sundial
Hello to all,
I am contemplating a temporary sundial sculpture
on the
horizontal dial, so azimuths are relative to this.
Good luck
Chris Lusby Taylor
51.4N 1.3W
- Original Message -
From: Keith E. Brandt, MD, MPH [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Sent: Wednesday, September 10, 2008 5:39 PM
Subject: Vertical South dial with horizontal gnomon
Sunny
Dear Bill,
I've been through the same decision-process. I have a computer-controlled
lathe and milling/engraving machine.
Some of my designs, like yours, are much more three-dimensional than
traditional sundials. But I've stayed with 2-D software, such as Corel Draw,
that can output DXF files,
Hi Patrick,
Unlike the mirrored dial that John refers to, yours doesn't have a gnomon, I
think.
Just a guess, but is it using polarisation? In your photographs the '6'
panels seem darker than the others, so I'm wondering if the tear-shaped
panels are polarised.
Could it be a sundial that can be
the latitude of the house.
The sundial geometry is greatly affected by latitude, as I'm sure you can
appreciate.
Also, do you have an unobstructed view of the sky in the directions in which
the sun rises and sets, or are there hills / buildings / whatever in the way?
Best wishes
Chris Lusby Taylor
accurately, as the gnomon is 40 degrees too steep and the hour lines are
hopeless (6am, noon and 6pm excepted!).
...or, perhaps, I've got it all wrong.
Chris Lusby Taylor
51.4N, 1.3W
- Original Message -
From: [EMAIL PROTECTED]
To: Frank.King [EMAIL PROTECTED]
Cc: sundial [EMAIL
Hi Tony,
I'm not 100% clear what you want to display. For instance, for -0.75 minutes
do you want -0 and -45 or -0 and 45 or 0 and -45? Or, doesn't it matter much
so long as any non-zero figure has the correct sign?
Also, for -4.483 do you want -4 and -28.98 or do you want the seconds
rounded to,
a great project. Let us know what results you get.
Chris Lusby Taylor
51.4N 1.3W
- Original Message -
From: Jos Kint
To: sundial@uni-koeln.de
Sent: Thursday, August 21, 2008 9:11 AM
Subject: Earth eccentricity
Hello all,
I am looking for some help in observing
I'm unimpressed. The watch shows that the sun is six minutes fast on
December 5th. But the Equation of Time on December 5th is about nine and a
half minutes.
Is that the best the watch industry can do? I'll stick with my sundials.
Chris
- Original Message -
From: Robert Terwilliger
Thanks Stijn,
I agree - the explanations there are first class. The two ways that Web site
offers of thinking about the equation of time element due to the obliquity
of the ecliptic are excellent.
Chris
- Original Message -
From: Stijn Helsen [EMAIL PROTECTED]
To: sundial@uni-koeln.de
Hi John,
Yes
Also, if the earth's orbit were a perfect circle, but the axis still tilted,
the four seasons (defined by the equinoxes and solstices) would all be the same
length, whereas currently the northern hemisphere spring/summer is a week
longer than the southern hemisphere's. There
Hi Doug,
The task of finding the shortest/quickest route from A to Z along a network
of roads is not the same as the Travelling Salesman Problem, nor its
generalisation the Vehicle Routing Problem, unless you also say you want to
go via C, D, E etc in no particular order but without visiting any
to
spring = the distance you move it from spring to summer, for all hours of
the day.
Too bad. But I like the 2:1 gearing idea. Mechanisms to do this are very
simple - the top of a pair of compasses is an example.
Chris Lusby Taylor
51.4N 1.3W
- Original Message -
From: Chris Lusby Taylor
of the solstices,
assuming the gnomon has moved by some arbitrary distance in the meantime.
Find the dial shape that would work for both dates (there will probably be
one) and see if it will work for all other dates.
Best wishes
Chris Lusby Taylor
- Original Message -
From: John Lynes [EMAIL
the mathematical expressions I've encountered in doing
sundials, though I haven't any personal experience of sending its output to
publishers.
Chris Lusby Taylor
51.4N 1.3W
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
an inscription readable after 180 degree
rotation or mirror imaging. I'm not sure you can see a stained glass design
from outside, though - doesn't it all look grey? My local church windows do.
Chris Lusby Taylor
51.4N 1.3W
- Original Message -
From: Mike Cowham
To: JOHN DAVIS ; John
Hi John,
I think the photo has been reversed.
An aerial photograph on www.multimap.com shows only one tall tree near the
path. It is on the east of the path, not the west. I believe the house now
belongs to English Heritage.
Chris Lusby Taylor
51.4N 1.3W
- Original Message -
From
altitude is 62 degrees
and one's shadow is less than three feet. It's a mistake to make the dial too
big. But the reclining mirror effectively reduces the sun's altitude to just 23
degrees so the shadow is greatly elongated and the dial can be made much bigger.
Hope this helps
Chris Lusby Taylor
Hi John et al,
I thought at first that John Lynes was making a joke, but you could actually do
this. If you have a large, fixed, plane mirror you can use the sunlight
reflected off it instead of the actual sun. By suitably angling the mirror you
can make the sun appear to rotate about any
not take account of the Equation of Time. It seems to me that it does,
in that the sun's positions along the ecliptic are plotted correctly. An
astrolabe is used as an altitude sundial, so does need to be corrected for
the EoT, but I'm pretty sure the sun disk does not.
Best wishes
Chris Lusby Taylor
sundiallers have huge
affinity with and respect for the astrolabe. I hope I don't seem critical of
the exquisite star disk - I just want to explore other possibilities.
Chris Lusby Taylor
51.4N, 1.3W (only 25 miles from the world's greatest collection of
astrolabes!)
- Original Message
), but that was
because he was driving a sun hand mechanically. You are not.
Best wishes
Chris Lusby Taylor
51.4N 1.3W
- Original Message -
From: James E. Morrison [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Sent: Wednesday, April 30, 2008 5:22 AM
Subject: Anaphoric Star Disk
Please excuse the cross
isn't
in the pictures, but the shadows seem to show that the southern sky is on
the south side of the disk.
Chris Lusby Taylor
- Original Message -
From: Chris Lusby Taylor [EMAIL PROTECTED]
To: James E. Morrison [EMAIL PROTECTED];
[EMAIL PROTECTED]
Sent: Wednesday, April 30, 2008 2:03 PM
here.
Chris Lusby Taylor
51.4N 1.3W
- Original Message -
From: Ricardo Cernic [EMAIL PROTECTED]
To: oglesby [EMAIL PROTECTED]
Cc: sundial sundial@uni-koeln.de
Sent: Friday, April 25, 2008 1:20 AM
Subject: Re:Request for suggestions
Hello Mac,
I know you intend to use stainless steel
could let the owners
know.
Chris Lusby Taylor
51.4N 1.3W
attachment: Warsaw_19.jpgattachment: Warsaw_BabyCropLo.jpgattachment: Warsaw_Ita.jpgattachment: Warsaw_BothCropLo2.jpg---
https://lists.uni-koeln.de/mailman/listinfo/sundial
like a business opportunity to me.
Chris Lusby Taylor
51.4N (for sure) 1.3W (for now)
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
/PWS_164a.jpg comes close.
Chris Lusby Taylor
51.4N 1.3W
- Original Message -
From: John Carmichael [EMAIL PROTECTED]
To: [EMAIL PROTECTED]; [EMAIL PROTECTED]
Cc: sundial@uni-koeln.de
Sent: Monday, April 21, 2008 10:16 PM
Subject: RE: A Most Beautiful Dial!
Hi Frans, Dave Others:
Can
other aspects of seasonality that a sundial can demonstrate? I'd
like to make it as relevant as possible to meteorology.
Regards
Chris Lusby Taylor
51.4N 1.3W
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
I believe the sun crossed the equator earlier today, so it's now summer here
in the Northern Hemisphere. Commiserations to all of you in the Southern
Hemisphere, especially as our summer is longer than yours.
Chris Lusby Taylor
51.4N 1.3W
---
https
: Simon [illustratingshadows [EMAIL PROTECTED],Chris
Lusby Taylor [EMAIL PROTECTED], [EMAIL PROTECTED]
Cc:
Data: Thu, 20 Mar 2008 20:11:39 +0200
Assunto: RE: Welcome to summer
Ah but our winters are sunny and dry
Les
South Africa
-Original Message-
From: [EMAIL PROTECTED
on Wednesday night.
Don't miss it (though in the UK it's rather late - about 3:15 to 3:40am).
The last total eclipse for several years. Not visible in Australia or east
Asia, I'm afraid.
Best wishes
Chris
- Original Message -
From: J. Tallman [EMAIL PROTECTED]
To: 'Chris Lusby Taylor' [EMAIL
or
growing.
Regards
Chris
- Original Message -
From: Frank King [EMAIL PROTECTED]
To: Chris Lusby Taylor [EMAIL PROTECTED]
Cc: sundial@uni-koeln.de; [EMAIL PROTECTED]
Sent: Sunday, February 17, 2008 6:22 PM
Subject: Re: Monumental Sundial; 14 missing seconds
Dear Chris,
I am a bit
Sabanski
www.mysundial.ca
I hope this helps.
Regards
Chris Lusby Taylor
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
the worst case
is ud=194 x r, or ud=97 D, which isn't far off the figure of 105 I had
before. The rule of thumb of making the diameter of a rod gnomon about
1/100th the distance to the dial is correct.
Very sorry for the confusion. Brain not in gear.
Chris Lusby Taylor
.
Regards
Chris Lusby Taylor
- Original Message -
From: JOHN DAVIS
To: [EMAIL PROTECTED] ; [EMAIL PROTECTED]
Cc: Sundial List
Sent: Wednesday, February 13, 2008 8:39 AM
Subject: Re: Shadow Tapering
Hi ChiLian,
That's very interesting - I haven't heard before of a dial
to Singapore. Practically on the Equator, so I'm working
on the use of existing buildings there. Or, perhaps, a building that inclined
1.3 degrees to the north. Would anyone notice such a small angle?
Chris Lusby Taylor
51.4N 1.3W
- Original Message -
From: Mashallah Ali-Ahyaie
Hi Doug,
It's Genk, not Ghent (which is Gand in Flemish and also spelt Gent, just to
confuse the foreigner). Try http://www.fransmaes.nl/genk/welcome-e.htm
Chris Lusby Taylor
- Original Message -
From: Douglas Bateman [EMAIL PROTECTED]
To: Sundial List [EMAIL PROTECTED]
Sent: Saturday
Thibaud,
I think it is you who is mistaken. The nadir of Mecca (21degrees 30'N,
39degrees 54'E) is surely 21degrees 30'S, 140degrees 6'W.
Chris Lusby Taylor
51.4N, 1.3W
- Original Message -
From: Th. Taudin Chabot
To: sundial@uni-koeln.de
Sent: Tuesday, July 17, 2007 12:44 PM
horribly dizzy if you
attempted it in a finite length of time. In fact, you'd have to spin
infinitely fast, which would take an infinite amount of energy, so it is
fair to say that it would take forever to reach a pole by following a rhumb
line.
Chris Lusby Taylor
51.4N 1.3W
- Original Message
there are overhangs - jaws and noses, for instance.
Chris Lusby Taylor
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
late. It appears that it's common knowledge amongst
housewives in this country.
Chris Lusby Taylor
51.4N 1.3W
- Original Message -
From: Edley McKnight
To: Roger Sinnott ; sundial@uni-koeln.de
Sent: Tuesday, June 05, 2007 6:59 AM
Subject: RE: Equation of Time
Hi Folks, just
Could you not, just as logically, ask why clocks, watches and normal sundials
don't indicate directly the time left until midnight?
Chris Lusby Taylor
51.4N, 1.3W
- Original Message -
From: Willy Leenders
To: sundial List
Sent: Monday, May 07, 2007 11:36 AM
Subject: Italian
Nice try, but the Ferguson in question was surely much later. The dial
illustrated in Cousins looks twentieth century. More Massey Ferguson than
James Ferguson. In fact, it looks like the prototype, minus the dolphins,
for Chris Daniel's dial at Greenwich.
The MHS's online register of Scientific
Sorry to bother the rest of you, but I'm trying to contact Juergen Hoefeld. He
emailed me recently but my reply to [EMAIL PROTECTED] couldn't be delivered and
caused my email program to lock up. It's taken me several hours to get it going
again.
So, there seems to be a problem with that
the polar gnomon and use the shadow of
the circle on it to indicate the date.
Best wishes
Chris
- Original Message -
From: robic.joel
To: fer de vries ; Chris Lusby Taylor ; Bill CS.Com ; sundial@uni-koeln.de
Sent: Friday, March 30, 2007 9:47 PM
Subject: Re: Article in March
.
Chris Lusby Taylor
51.4N 1.3W
- Original Message -
From: Bill CS.Com
To: sundial@uni-koeln.de
Sent: Thursday, March 29, 2007 7:31 PM
Subject: Article in March BSS bulletin
I want to recommend Chris Lusby Taylor's article in the March BSS Bulletin
on Italian/Babylonian
for any date.
Thank you APH.
Chris Lusby Taylor
51.4N 1.3W
..---
https://lists.uni-koeln.de/mailman/listinfo/sundial
the 30/60 and 90/100 positions. The other
two hands are not in those positions, but perhaps they have been placed
incorrectly on their arbours.
Regards and a Happy New Year to all
Chris Lusby Taylor
51.3N, 1.4W
- Original Message -
From: Robert Terwilliger [EMAIL PROTECTED]
To: 'Mac
are actually
for the Italian and Babylonian hours, and the lines parallel to them needed to
read conventional hours, is to create an attractive grid of triangles.
Hope this helps
Regards
Chris Lusby Taylor
- Original Message -
From: mohammad reza noruzi
To: sundial@uni-koeln.de
Dear Joe,
Have you tried Google?
It's first entry is
http://www.arts.manchester.ac.uk/subjectareas/history/academicstaff/penelopegouk/
which tells you everything you wanted to know.
Regards
Chris
- Original Message -
From: newmail [EMAIL PROTECTED]
To: Sundial list sundial@uni-koeln.de
as it would be if the orbit were circular.
But this correction is so small you may ignore it in practice if you
wish.
I thought I'd invented this construction (it isn't in
Cousins or any of the other common sundial books) but have found that it has
been known for centuries!
Chris Lusby Taylor
51.4N
Hi Tracy,
You say " I may make lines that radiate from the center
out to the hour marks anyway." Please don't.
The hour marks are on the ellipse. The shadow falling on,
say, the 10 o'clock mark comes from a different direction depending on the time
of year. By standing on the correct date
Hi Tracy,
The date scale should be on the N-S centreline of the
elliptical dial (i.e. the minor axis of the ellipse). The position of the 12
noon point is irrelevant.
3 feet by 10 feet is a big scale. How big is the
dial?
Regards
Chris
- Original Message -
From:
Tracy Paine
Hi All,
Rather than making two shepherd's dials - one for the
morning, one for the afternoon - you could divide its 360 degree circumference
into two 180 degree sections, one for the morning, one for the afternoon. Then
there's only one set of hour lines on each side.
With a shepherd's
Hi Warren,
There are many ways to express and solve the geometric relationships
encountered in sundialing. In earlier times, geometric methods, such as
nomograms and dialling scales, were developed. One, presented by Fred Sawyer
at a BSS Conference some years ago and published in the NASS
Actually, I thought "historical reenactment" and "standard
mean time" are sort of mutually exclusive.
Most mean time dials have uniform 15 degree hour spacing,
so setting zone time, daylight saving, or whatever, is just a matter of rotating
the dial. Of these, the most portable form is the
At 11:52 AM 9/1/2006 -0700,
John Carmichael wrote: Hello
Roger (Sinnott): Humm... I read your concerns that a three
sided pyramid and a 3 sided post are problematic gnomons.
And I tried to understand
your reasoning, but for the life of me, I can't understand the problem you
mention. I
Hello Greg,
Let's ignore refraction for a moment, and just think about the celestial
hemisphere above your horizon.
When the sun transits at noon it is in the North-South plane that cuts the
hemisphere in two. But it isn't necessarily directly overhead. In fact it
won't be directly overhead on
Hi Thyge,
Thank you for your contribution to this interesting
debate. Your sundial is stunning. Trust the Danes to show the rest of the world
how to apply good modern design ideas to old products.
Yes, we had realised that a circular disk parallel to the
wall would cast a circular shadow.
(Sorry all. I just sent this with my date set to May 2005,
to calculate the sun's position. That's twice I've done that in one week!
Profuse apologies. Chris)
Hi Thyge,
Thank you for your contribution to this interesting
debate. Your sundial is stunning. Trust the Danes to show the rest of
in free sun position programs.
Next time I'm directing a feature film I think I'll use
one.
Cut!
Chris Lusby Taylor
51.4N, 1.3W, sun currently: behind a cloud.
- Original Message -
From:
Fred Sawyer
To: Sundial List
Sent: Thursday, May 18, 2006 3:01
AM
Subject: Fw: New
Sorry to those to whom I inadvertently sent this. I meant to send it to the
list. I think I have now done so.
- Original Message -
From: Chris Lusby Taylor [EMAIL PROTECTED]
To: Robert Terwilliger [EMAIL PROTECTED]
Sent: Wednesday, May 17, 2006 4:55 PM
Subject: Re: Sundial Motif
prefer the simpler term 'equatorial'.
Yes, they are synonymous.
Chris Lusby Taylor
- Original Message -
From: [EMAIL PROTECTED]
To: sundial@uni-koeln.de
Sent: Wednesday, May 17, 2006 6:21 PM
Subject: taxonomy?
Is there a formal taxonomy for sundials?
I like:
http://sundials.org/faq
I'm just worried for Chris Daniel. Will his body be found
floating in the Cam under a famous bridge associated with a well-known
astrologer, moondial maker and, allegedly, member of the Priory of Sion? If so,
I'd look for aconnection with the only Royal Navy officer ever to have had
his VC
Dear Mike, Frans all,
I think this goal is absolutely the most important thing we can do to
improve the appreciation of sundials by the general public. Wouldn't it be
nice if we could make non-dials unsellable by educating people into what
makes a real sundial. At the same time, we can educate
Hi John et al,
If you want a circular shadow that doesn't elongate when
the sun is at a small angle to the dial face, you can use a circular disc, held
parallel to the plane of the dial. A large disc witha small circular hole
in the middle works very well, too.
The tip of a cone is an
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