Re: Dyptich sundial - help!

[rodwall1...@gmail.com]

Hi,
Some more interesting information on the Boy Scouts Sun Watch.

http://www.vintagerecipeblog.com/2016/03/the-ansonia-sunwatch-instructions.html?m=1

Note that the gnomon is not a string.

Regards,

Roderick Wall.

- Reply message -
From: "rodwall1...@gmail.com" 
To: "Michael Ossipoff" , "Schechner, Sara" 

Cc: "Sundial List" 
Subject: Dyptich sundial - help!
Date: Sun, Aug 12, 2018 7:31 AM

Hi,
For those who are interested. A Boy Scout Sun Watch.
https://m.ebay.com.au/itm/RARE-1920-1922-ANTIQUE-BOY-SCOUTS-SUN-WATCH-COMPASS-ANSONIA-Co-NY/132733705686?hash=item1ee78b9dd6%3Ag%3AXFsAAOSw0lVa7z7H&_nkw=sun+watch+boy+scout&_from=R40=nc

Regards,

Roderick Wall.

- Reply message -
From: "Michael Ossipoff" 
To: "Schechner, Sara" 
Cc: "Sundial List" 
Subject: Dyptich sundial - help!
Date: Sat, Aug 11, 2018 7:38 AM

Sara and John--

But it's said that the hour-lines for Babylonian, Italian, and co-Italian
hours are straight lines, as they are on all the other dials that I've seen
that have Babylonian &/or Italian hours.

Michael Ossipoff

On Fri, Aug 10, 2018 at 4:37 PM, Schechner, Sara 
wrote:

> I am camping at Stellafane with little connection, so will keep this brief
> until I return to civilization!
>
> The gnomon is adjustable for different latitudes.  The choice determines
> the correct horizontal scale to use around the compass.  The 2 pin gnomon
> scaphe sundial are for finding Italian and Babylonian (or Nuremberg
> hours).  The instrument with the spinning pointer is a wind vane.
> The instrument is made in Nuremberg in the early 17th century.
>
> Sara
>
> Sent from my iPhone
>
> On Aug 10, 2018, at 12:48 PM, Michael Ossipoff 
> wrote:
>
> Yes, the Boy Scouts of America at least used to sell a Compass-Oriented
> Dyptich dial with several concentric rings, each having different
> hour-lines, and with its string-gnomon adjustable for latitude, with
> several attachment-points on the vertical surface. I think it accommodated
> 3 latitudes. The hour-line rings were rectangular, it seems to me.
>
> Someone at this forum designed a universal Horizontal-Dial whose hour
> lines were curved lines originating from the gnomon-string's
> base-attrachment, with latitude-labeled concentric circles telling where to
> read the hour lines for the various latitudes.  ...and of course with the
> string-gnomon slidable in a vertical slot in the vertical surface.
>
> Michael Ossipoff
>
>
>
> On Fri, Aug 10, 2018 at 4:22 AM, Dan-George Uza 
> wrote:
>
>> Dear all,
>>
>> I've recently found this piece in a museum near me and I need your help
>> in dating it.
>>
>> Why are the hour marks offset? I suspect a correction for latitude. And
>> what do the two small circular dials on the bottom measure?
>>
>> Also what would be the purpose of the circular shape containing the
>> alidade? I suspect it has something to do with the winds.
>>
>> Any info will be highly appreciated.
>>
>> Thank you,
>>
>> Dan Uza
>>
>>
>>
>>
>> ---
>> https://lists.uni-koeln.de/mailman/listinfo/sundial
>> <https://urldefense.proofpoint.com/v2/url?u=https-3A__lists.uni-2Dkoeln.de_mailman_listinfo_sundial=DwMFaQ=WO-RGvefibhHBZq3fL85hQ=7ZsgDX5inZSMERqhZEQacOtdADP0iy6-YB7dx6Z_mVo=3-DALhUvBQJn8P9cKR9FHS3EG06h7iYhIPEnqd_W0kI=ifZ07QqBi_JWsaekGzvK_IWYmTdGpp6kYF_t_p0_shI=>
>>
>>
>>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Dyptich sundial - help!

[rodwall1...@gmail.com]

Hi,
For those who are interested. A Boy Scout Sun Watch.
https://m.ebay.com.au/itm/RARE-1920-1922-ANTIQUE-BOY-SCOUTS-SUN-WATCH-COMPASS-ANSONIA-Co-NY/132733705686?hash=item1ee78b9dd6%3Ag%3AXFsAAOSw0lVa7z7H&_nkw=sun+watch+boy+scout&_from=R40=nc

Regards,

Roderick Wall.

- Reply message -
From: "Michael Ossipoff" 
To: "Schechner, Sara" 
Cc: "Sundial List" 
Subject: Dyptich sundial - help!
Date: Sat, Aug 11, 2018 7:38 AM

Sara and John--

But it's said that the hour-lines for Babylonian, Italian, and co-Italian
hours are straight lines, as they are on all the other dials that I've seen
that have Babylonian &/or Italian hours.

Michael Ossipoff

On Fri, Aug 10, 2018 at 4:37 PM, Schechner, Sara 
wrote:

> I am camping at Stellafane with little connection, so will keep this brief
> until I return to civilization!
>
> The gnomon is adjustable for different latitudes.  The choice determines
> the correct horizontal scale to use around the compass.  The 2 pin gnomon
> scaphe sundial are for finding Italian and Babylonian (or Nuremberg
> hours).  The instrument with the spinning pointer is a wind vane.
> The instrument is made in Nuremberg in the early 17th century.
>
> Sara
>
> Sent from my iPhone
>
> On Aug 10, 2018, at 12:48 PM, Michael Ossipoff 
> wrote:
>
> Yes, the Boy Scouts of America at least used to sell a Compass-Oriented
> Dyptich dial with several concentric rings, each having different
> hour-lines, and with its string-gnomon adjustable for latitude, with
> several attachment-points on the vertical surface. I think it accommodated
> 3 latitudes. The hour-line rings were rectangular, it seems to me.
>
> Someone at this forum designed a universal Horizontal-Dial whose hour
> lines were curved lines originating from the gnomon-string's
> base-attrachment, with latitude-labeled concentric circles telling where to
> read the hour lines for the various latitudes.  ...and of course with the
> string-gnomon slidable in a vertical slot in the vertical surface.
>
> Michael Ossipoff
>
>
>
> On Fri, Aug 10, 2018 at 4:22 AM, Dan-George Uza 
> wrote:
>
>> Dear all,
>>
>> I've recently found this piece in a museum near me and I need your help
>> in dating it.
>>
>> Why are the hour marks offset? I suspect a correction for latitude. And
>> what do the two small circular dials on the bottom measure?
>>
>> Also what would be the purpose of the circular shape containing the
>> alidade? I suspect it has something to do with the winds.
>>
>> Any info will be highly appreciated.
>>
>> Thank you,
>>
>> Dan Uza
>>
>>
>>
>>
>> ---
>> 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: Is this sundial business 'genuine', or not?

[rodwall1...@gmail.com]

Hi Rodger,
Thanks for the discretion.

Best regards,

Roderick Wall.

- Reply message -
From: "Roger" 
To: "rodwall1...@gmail.com" , "Michael Ossipoff" 

Cc: "sundial list" 
Subject: Is this sundial business 'genuine', or not?
Date: Mon, Jul 23, 2018 3:28 AM

Apply Occam’s Razor. A table is a table consisting of a flat horizontal surface 
typically on four legs. Get down means kneeling, sitting or crouching beside 
the table with your eye at the height of the table and viewing across the 
table. You see the table top as a line in this one dimensional view. You can 
see the equatorial disc and the pencil in a two dimensional view with the disc 
at the sloping up at the co-latitude angle and the pencil (gnomon) at an angle 
to the plane of the table . You turn the disc and pencil to see it in 2 not 3 
dimensions. The whole concept is based on taking different points of view, 
straight down from the top, straight across from the side, along on a plane 
etc. This is what engineering drawing is based on. Descriptive geometry and 
graphical design are offshoots. Do they teach this any more? It was a key part 
of the education of engineers and draftsmen when I took it almost 60 years ago. 
The concepts remain valid. 

For further information come to the NASS conference next month for the 
presentation on “Alternative Seasonal Markers for Analemmatic Sundials” by 
Chris Lusby Taylor and Roger Bailey. This presentation includes over 30 slides 
going through the graphical design technique step by step and solving for exact 
seasonal markers, points on the major axis used with the date/declination table 
to show when and where the sun rises and set through the year. The steps are 
basic and the solution remarkable simple. In trig terms, X = a (Cos Lat) 
squared.

Publication as an article? Not if it takes 30 x 1000 words!

Regards,
Roger Bailey
Walking Shadow Designs

From: rodwall1...@gmail.com
Sent: July 21, 2018 1:59 PM
To: Michael Ossipoff; Roger
Cc: sundial list
Subject: Re: Is this sundial business 'genuine', or not?

Hi Rodger,

Thanks for the description on how to graphical design a analemmatic sundial.

It maybe me but I am having problems in following your instructions. I find it 
very hard to follow some parts like.

"Now physically drop the disc and pencil onto a horizontal table. Get down to 
view across the table and turn the disc to see it on edge. It will be seen as a 
true length straight line equal to the diameter of the circle."

Does this mean onto a table with legs, or are you referring to a table flat on 
the ground, the sundial is to be on the ground? When you get down onto the 
table. Which way do you face and which way do you turn the disc to see it on 
the edge? And how do you see the edge of the disc as a straight line and where 
does the true length fit in. 

It maybe me but I am lost as to what it means. Please don't think I am being 
negative. I just want to understand how to use this method to draw analemmatic 
sundials. I think it would be a great method if I could only understand it.

I don't know if you have the time to perhaps add some drawings to also show 
each step? I think some drawings may help me to understand it better. They say 
a drawing replaces a 1,000 words.

There also maybe teachers in this group who also find it hard to follow. They 
might want to use this method in their classroom.

Thank,

Roderick Wall.

- Reply message -
From: "Michael Ossipoff" 
To: "Roger" 
Cc: "sundial list" 
Subject: Is this sundial business 'genuine', or not?
Date: Sat, Jul 21, 2018 8:09 AM


Roger--

I re-emphasize that I'm not attacking the validity of your explanation. As
I said, the sundial-construction explanations based on an orthographic
projection never made sense to me. I'm not saying that they aren't valid,
only that weren't helpful to me.

It seems to me that, when you seek to explain the Analemmatic without the
trig, then, by the time you cover everything relevant to it, without
leaving unanswered questions--then you end up with something much more
complicated and difficult than the trig explanation.

Michael Ossipoff

On Tue, Jul 17, 2018 at 7:31 PM, Roger  wrote:

> Hi Jack and Michael,
>
>
>
> I don’t agree. The concept is very simple. Perhaps you have had bad
> teachers. One of my presentations at the upcoming conference is a purely
> grapghical method of designing an analemmatic sundial. No trig, not even
> geometry other than the Greek’s ruler and string or a simple math set with
> ruler, protractor and a compass.  From this graphical technique comes a
> whole new concept by  Chris Lusby Taylor for seasonal makers that I will
> describe at the conference next month.
>
>
>
> To demonstrate the simple concepts for analemmatic sundials, start with
> this experiment as a class activity, hands on and interactive. Cut out a
> circle o

Re: Is this sundial business 'genuine', or not?

[rodwall1...@gmail.com]

Hi Rodger,
Thanks for the description on how to graphical design a analemmatic sundial.

It maybe me but I am having problems in following your instructions. I find it 
very hard to follow some parts like.

"Now physically drop the disc and pencil onto a horizontal table. Get down to 
view across the table and turn the disc to see it on edge. It will be seen as a 
true length straight line equal to the diameter of the circle."

Does this mean onto a table with legs, or are you referring to a table flat on 
the ground, the sundial is to be on the ground? When you get down onto the 
table. Which way do you face and which way do you turn the disc to see it on 
the edge? And how do you see the edge of the disc as a straight line and where 
does the true length fit in. 

It maybe me but I am lost as to what it means. Please don't think I am being 
negative. I just want to understand how to use this method to draw analemmatic 
sundials. I think it would be a great method if I could only understand it.

I don't know if you have the time to perhaps add some drawings to also show 
each step? I think some drawings may help me to understand it better. They say 
a drawing replaces a 1,000 words.

There also maybe teachers in this group who also find it hard to follow. They 
might want to use this method in their classroom.

Thank,

Roderick Wall.

- Reply message -
From: "Michael Ossipoff" 
To: "Roger" 
Cc: "sundial list" 
Subject: Is this sundial business 'genuine', or not?
Date: Sat, Jul 21, 2018 8:09 AM

Roger--

I re-emphasize that I'm not attacking the validity of your explanation. As
I said, the sundial-construction explanations based on an orthographic
projection never made sense to me. I'm not saying that they aren't valid,
only that weren't helpful to me.

It seems to me that, when you seek to explain the Analemmatic without the
trig, then, by the time you cover everything relevant to it, without
leaving unanswered questions--then you end up with something much more
complicated and difficult than the trig explanation.

Michael Ossipoff

On Tue, Jul 17, 2018 at 7:31 PM, Roger  wrote:

> Hi Jack and Michael,
>
>
>
> I don’t agree. The concept is very simple. Perhaps you have had bad
> teachers. One of my presentations at the upcoming conference is a purely
> grapghical method of designing an analemmatic sundial. No trig, not even
> geometry other than the Greek’s ruler and string or a simple math set with
> ruler, protractor and a compass.  From this graphical technique comes a
> whole new concept by  Chris Lusby Taylor for seasonal makers that I will
> describe at the conference next month.
>
>
>
> To demonstrate the simple concepts for analemmatic sundials, start with
> this experiment as a class activity, hands on and interactive. Cut out a
> circle of cardboard. Stick a pencil through the center at a right angle to
> the disc. Hold it with the pencil vertical. Look straight down on the disc,
> a circle true size. Hour angles drawn every 15° would also be true angles.
> The pencil is seen as a point. Now physically drop the disc and pencil onto
> a horizontal table. Get down to view across the table and turn the disc to
> see it on edge. It will be seen as a true length straight line equal to the
> diameter of the circle. The pencil will also be seen a true length line. If
> you chose the right length of pencil, the pencil will make an angle to the
> horizontal equal to your latitude. The disc will make an angle to the
> co-latitude.  Now get up and look straight down on the disc and pencil on
> the table. The disc will be seen as an ellipse and the pencil as a shorter
> line as neither disc or pencil are true length. Look at it straight down
> from above and mark the point on the desk that is directly under the end of
> the hour mark on the disk starting with the disc turned to the starting
> point noon being directly under the pencil. These points define. the hour
> ellipse for an analemmatic sundial.
>
>
>
> Next the enigmatic date line. Consider the sun shining down at noon at any
> day of the year onto the pencil through the disc on the table. The sun
> shines down on the pencil and there is a unique point on the pencil each
> day where the sun at noon shines directly onto the rim of the disc. At the
> summer solstice the sun is high in the sky. The angle of the suns ray down
> to the disc rim is at an angle of 23.5° to the disc. At the winter solstice
> the angle is -23.5 ° On the spring and fall equinox the angle is 0°. Every
> day has a different angle, the solar declination for that day. Now you
> could switch to ruler and protractor marking on paper right angle
>  triangles with the base equal to the disc radius. Measure angles from the
> base point up at the chosen declination angle and draw a line at that angle
> to the line at right angles to the other end of the base line for the
> declination points for the chosen dates. Now draw a line for the horizon at
> an angle to the disc base 

Re: Is this sundial business 'genuine', or not?

[rodwall1...@gmail.com]

Hi Roger and Mitchael,
I'm sure others have thought of and have used these concepts before us. 
Sundials have been around for a long time.

What these concepts achieves are:

That all clocks have a energy source to make them work. For sundials it is the 
rotation of Earth. And that planet Earth rotates (moves) in relation to the 
sun. It is not the sun that moves. We often say that the sun moves across the 
sky. But it is planet Earth that rotates and moves. This is important to be 
able to fully understand how a sundial works.

It also shows that sundials are geared to the rotation of planet Earth wherever 
they are located on Earth. It completes what makes the sundial moves in 
relation to the sun.

Once the concept on how a Equatorial sundial or disk dial works at the South or 
North pole works. The Equatorial sundial or disk sundial can then be used to 
draw the hour lines on a horizontal or vertical sundial. There is a complete 
connection between all concepts. Not just part of it.

And it describes it for both hemispheres not just for the Northern hemisphere. 
Sundial are also located in the Southern hemisphere.

It can also be used to show that sundial hours on the dial face runs clockwise 
in the Northern hemisphere and anticlockwise in the southern hemisphere. 

I remember reading somewhere that. The reason that clock hours run clockwise is 
because sundials in the Northern hemisphere had their hours running clockwise. 
Someone may like to comment as to if this is true.

In a classroom a globe or beach ball can be used to show the above concepts. 
Then the students could then use a Equatorial or disk sundial to draw hour 
lines on their own sundial. Then go outside in the sun to test their sundial. 
But 1st make sure they have their hats on and suntan oil on to protect them 
from the sun. That is what they do in sunny Australia.

Have fun,

Roderick Wall.

---
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Re: Is this sundial business 'genuine', or not?

[rodwall1...@gmail.com]

Hi all,
The following is what I think is the best way to describe how sundials work to 
kids or anyone.


1st start with the largest sundial in the world. Planet Earth the Master 
sundial clock. Stick a vertical stick into the ground at the South pole or 
North pole. And describe how the shadow shows the time throughout the day. Draw 
the 24 hour lines every 15 deg and that 15 deg x 24 hours = 360 deg one day.

Then show how the Equatorial sundial relates to our stick sundial at the poles. 
Place it at the South or North pole. And show that the Equatorial sundial style 
edge is parallel with the stick and the axis of the Earth. And that the hour 
lines are the same every 15 deg. And that it will keep the same time.

Then place the Equatorial sundial anywhere on earth. And show that the sundial 
is geared to Earth the largest sundial in the world (the Master sundial clock). 
Therefore it will keep the same time. Show how the sundial time markings relate 
to your local time. And that the style edge of the sundial must be parallel 
with the axis of the earth and parallel with the vertical stick at the poles. 
And that at night time the sundial is in the shadow of Earth.

Then place a horizontal sundial at the same location. And describe that the 
style edge is also placed parallel with the stick and the axis of the Earth. 
And how the hour lines are projected every 15 deg from the horizontal sundial 
style. That is to place the style edge of the equatorial sundial onto the 
horizontal sundial style edge and use it to project the hour points onto the 
horizontal base of the horizontal sundial. Then draw the hour lines on the 
horizontal sundial. Then show the direction the horizontal sundial faces if in 
the Southern hemisphere or Northern hemisphere. To ensure that the Style edge 
is parallel with the axis of the Earth and stick.

Then go through the same process as you did for the horizontal sundial but with 
a vertical sundial on a wall. And show that it must face North towards the sun 
if in the southern hemisphere and face South for the northern hemisphere. Yes I 
live in sunny Australia in the southern hemisphere.

Then show how the angle of the style edge relates to the latitude of the 
location of the sundial. To make the style edge parallel with the stick and 
axis of the Earth.

Depending on how far you want to go. Describe how a horizontal sundial that is 
not designed for the  latitude of the location you are at. Can be corrected if 
a block is placed under the dial to make the style edge parallel with the axis 
of the Earth and the stick.

Describe how longitude relates to your location. And that the longitude time 
zones are every 15 deg. 15 deg x 24 hours = 360 deg one day.

One way to describe the above is to use a globe of the world or a large beach 
ball. With cardboard cutouts for sundials. And a lamp (sun) to make the 
shadows. Young kids and some adults learn better when learning in the sand pit 
(concrete learning) rather that just using symbolic words (symbolic learning).

That is how I explain it.

If anyone wants to publish the above. Please do and let them know where it came 
from.

Have fun,

Roderick Wall
Sunny Australia.

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

Re: sundial Digest, Vol 149, Issue 13

[rodwall1...@gmail.com]

Hi,
What about a English version?

Regards,

Roderick Wall.

- Reply message -
From: "Lupe F." 
To: "sundial@uni-koeln.de" 
Subject: sundial Digest, Vol 149, Issue 13
Date: Sun, May 20, 2018 3:16 AM

Hi friends,
I would like to add that in that last La Busca de paper (the SCC magazin), you 
can find an article written by me. ;)
It is at pages to 15 to 17.
If anyone is interested on the Spanish version, I have it.
In fact, this article was written in Spanish.
Regards
Lupe Feria


El 19 may. 2018 11:27 a. m., sundial-requ...@uni-koeln.de escribió:

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When replying, please edit your Subject line so it is more specific
than "Re: Contents of sundial digest..."


Today's Topics:

1. LA BUSCA DE PAPER N?mero 89 (Reinhold Kriegler)


--

Message: 1
Date: Sat, 19 May 2018 11:27:42 +0200
From: Reinhold Kriegler 
To: Sundial Mailing List 
Subject: LA BUSCA DE PAPER N?mero 89
Message-ID: <258111284.20180519112...@gmx.de>
Content-Type: text/plain; charset="windows-1252"

Dear sundial friends,

a most beautiful new issue of the Catalan sundial society magazine
LA BUSCA DE PAPER
has been edited!



The article starting on page 4, written by Mohamad Soltanolkotabi
is availabe in a free PDF-version. Do not miss to download it and keep it until
2026!
2026/2028: Una oportunitat ?nica per deixa-se eclipsar

http://www.gnomonica.cat/files/BdP89-article.pdf

SOCIETAT CATALANA DE GNOM?NICA:
http://www.gnomonica.cat/


Enjoy!

Reinhold Kriegler

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

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/dies-und-das/das-b-a-u-h-a-u-s-museum-in-dessau-rosslau.html
http://www.ta-dip.de/dies-und-das/die-niederpoeringer-radrennbahn.html
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End of sundial Digest, Vol 149, Issue 13
---
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Education sundial in Australia

[rodwall1...@gmail.com]

Hi all,
I have just purchased a plastic educational sundial from Kmart in Burwood 
Victoria Australia. For AU$2.00. Looks like a clearance sale.

Other Kmarts in Australia may also have them?

It is called "Sundial Build and play" by STEM LEARNING. Barcode: 9 341104 
583688. 

You can set the Gnomon to different latitude angles in 5 deg steps. And has 
different hour line cards suitable for Darwin, Brisbane, Perth, Adelaide, 
Melbourne, Sydney, Auckland New Zealand and Wellington New Zealand.

It even has a small compass. And a set of instruction and a bit on how a 
sundial works.

Thought others in Australia may like to purchase one?

Best regards,

Roderick Wall.

---
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Re: From sundial to sundial along a meridian to Cistercian abbeys

[rodwall1...@gmail.com]

Hi Willy,
Thanks it was very interesting to read about the trip.

About the different Abbeys and sundials. Being there for many hundreds of 
years. Where here in Australia I remember as a child our town became 100 years 
old.

Thanks,

Roderick Wall.

- Reply message -
From: "Willy Leenders" 
To: "Sundial sundiallist" 
Cc: "Ginny Haesevoets" , "Wim Van Lishout" 
, "Karolien Mondelaers" , 
"Irene Bien" 
Subject: From sundial to sundial along a meridian to Cistercian abbeys
Date: Fri, Nov 24, 2017 8:14 AM

Dear all,

On a garden path in the herb and inspiration garden of the abbey site 
Herkenrode in Hasselt (Flanders in Belgium) is situated an analemmatic sundial 
and a continuous meridian line of 225 meters, the longest in the world.
530 km to the south, in Brou (Bourg en Bresse - France), almost on the same 
meridian is situated the oldest known analemmatic sundial.

In between, not so far from the meridian, left and right there are important 
remains of medieval Cistercian abbeys including Orval, Clairvaux, Fontenay and 
Cîteaux.
Interesting cities in the area are Reims, Troyes and Beaune. 

A group of friends from Herkenrode, also a former Cistercian abbey, did its 
fifteenth annual trip to Cistercian Abbeys in Europe in September 2017 under 
the slogan “From sundial to sundial along a meridian to Cistercian abbeys"

An illustrated and documented report of that trip can be found on my website on 
page http://www.wijzerweb.be/fromsundialtosundial.html


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

Re: Sundial books for children

[rodwall1...@gmail.com]

I think the best way to teach 10 year olds. Is not by a book but by active 
doing and seeing.
Part of active seeing could be to have a sundial and use a torch as being the 
sun. Describe the torch as being the sun, and watch the shadows show the time. 
Describe that in the morning the sun comes up in the east. Then show noon time. 
Then show the afternoon times until sunset. That makes the connection as to how 
the shadows shows the time.

Some 10 year olds are active learning and are sand pit learners. Not symbolic 
learners from a book or black board.

Regards,

Roderick Wall.

- Reply message -
From: "Willy Leenders" 
To: 
Subject: Sundial books for children
Date: Mon, Nov 6, 2017 5:26 AM

Always teach children from the beginning that they should stand on the 
centerline of 'the calendar' of an analemmatic sundial and not on the month 
like most of the images on this website!

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 5-nov-2017, om 18:01 heeft Paul Ratto het volgende geschreven:

> In message 
> 
>  Michael Ossipoff  wrote:
> 
>> Show them sundials that can be explained to them. I think that people will
>> like something better, enjoy it more, if they know how it works.
>> 
>> As much as I like the Analemmatic Dial, I prefer (at least at first)
>> showing people sundials that they'd be willing to listen to an explanation
>> of.   ...or dials whose explanation is brief.
>> 
>> So, that would rule-out the Analemmatic, and declining flat dials, and
>> altitude dials.
>> 
>> The Horizontal Dial, closely derived from the Equatorial Dial, has a brief
>> and intuitive explanation. Likewise the South Vertical  Dial, the Polar
>> Dial, and any north or south Reclining Dial. (They're like Horizontal Dials
>> for different latitudes). (They could be summarized as any dial whose
>> plate's normal is in the plane of the meridian).
>> 
>> Of course the Equatorial Dials are the most obvious and natural of all, not
>> really requiring explanation. (By "Equatorial", I mean any dial that
>> directly shows a shadow's or lightspot's movement around the equatorial
>> plane by uniformly-spaced marks around a circle in that plane)
>> 
>> My favorite for a south windowsill is the Circumference-Aperture
>> Cylinder-Equatorial, but I'd want to include, with it, at least a
>> *description* of the geometric demonstration of its principle. (My
>> girlfriend doesn't care for geometry or math, but she's going to hear about
>> the geometry of a Circumference-Aperture Cylindrical-Equatorial.)
>> 
>> Declining flat dials, altitude dials, the Analemmatic Dial, and the
>> Circumference-Aperture Cylinder-Equatorial are good ways of inspiring
>> interest in, and demonstrating, some geometry or astronomical mathematics.
>> Emphasize to  the person, that those subjects are relevant and interesting,
>> and useful.
>> 
>> It seems to me that those dials would be especially a good idea for school
>> math classes, or for when someone's child is taking such courses.
>> 
>> Michael Ossipoff
>> 
> 
> 
> Although I am not aware of Sundial books written SPECIFICALLY for
> children, several (mainly Analemmatics due to their 'interactive'
> nature) are certainly featured within some School-books - and you
> could view examples at website: www.sunclocks.com/data/school.htm
> 
> If you want to interest children in the subject of Sundials - then
> I suggest that you visit some Schools and give a 'presentation' to
> them - as in the attached photograph, showing Slaven Licina giving
> such a talk.  You can visit his own website at: www.suncanisat.com
> 
> Regards,
> 
> Paul Ratto.
> 
> 
>> 
>> 
>> On Sun, Nov 5, 2017 at 10:46 AM, Dan-George Uza 
>> wrote:
>> 
>>> Hello,
>>> 
>>> I am looking for titles of sundial books for children. I particularly
>>> liked Annos sundial pop-up book by Mitsumasa Anno. Also, I would like to
>>> know some of your experiences in working with kids. What do you think is
>>> the best approach to teach 10 year olds about sundials?
>>> 
>>> Regards,
>>> 
>>> Dan Uza
>>> 
>>> ---
>>> 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: publication on Science of Time, with sundials

[rodwall1...@gmail.com]

Thanks Sara,
A very interesting book. Haven't finished reading it but will.

It reminds me of a book that I once read about time.

Book indicated that when the telegraph lines were invented. This then allowed 
time to be accurate at the end of the telegraph line. Which then allowed the 
location longitude to be accurately defined. And more places as the telegraph 
lines were extended. And even more places when wireless was invented.

Time is very interesting.

John Harrison's Longitude watch also allowed the longitude to be determined 
more accurately at sea. The story of Longitude and time.

Regards,

Roderick Wall. 
At the end of the line in Australia.

- Reply message -
From: "Schechner, Sara" 
To: "Richard Langley" 
Cc: "sundial@uni-koeln.de" 
Subject: publication on Science of Time, with sundials
Date: Fri, Nov 3, 2017 6:50 AM

Dear All,
The links were free to me and others, but perhaps we are somehow inside the 
firewall.  I don't understand what is going on, since I have not logged into 
the Springer site.  

Here is a link to my download of the book: 
https://www.dropbox.com/s/uly1qfaov3intr1/Science%20of%20Time%202016%20BOOK_978-3-319-59909-0.pdf?dl=0
   

I hope this will help.
Sara


-Original Message-
From: Richard Langley [mailto:l...@unb.ca] 
Sent: Thursday, November 02, 2017 3:27 PM
To: Schechner, Sara
Cc: sundial@uni-koeln.de
Subject: Re: publication on Science of Time, with sundials

For free? Not when I followed the links.
-- (Prof.) 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/   |
-



> On Nov 2, 2017, at 3:43 PM, Schechner, Sara  wrote:
> 
> Dear Friends,
>  
> In June 2016, I attended a symposium on the Science of Time.  The 
> proceedings have now been published by Springer, and are available for 
> free download here:  
> https://link.springer.com/book/10.1007/978-3-319-59909-0
>  
> The Science of Time 2016: Time in Astronomy & Society, Past, Present 
> and Future Edited by  Elisa Felicitas Arias, Ludwig Combrinck, Pavel Gabor, 
> Catherine Hohenkerk, and P. Kenneth Seidelmann.
> Astrophysics and Space Science Proceedings, vol 50.
> Cham: Springer International Publishing AG, 2017
>  
> Many articles may be of interest to this group, but in particular there are 
> two articles on sundials.  I list them below along with direct links ot the 
> PDFs:
>  
> Geoff Parsons:  “The Development and Use of the Pilkington and Gibbs 
> Heliochronometer and Sol Horometer”
> https://link.springer.com/content/pdf/10.1007%2F978-3-319-59909-0_7.pd
> f
>  
> Sara J. Schechner:  “These Are Not Your Mother’s Sundials: Or, Time and 
> Astronomy’s Authority”
> https://link.springer.com/content/pdf/10.1007%2F978-3-319-59909-0_8.pd
> f
>  
> Happy reading!
> Sara
>  
> Sara J. Schechner, Ph.D.
> David P. Wheatland Curator of the Collection of Historical Scientific 
> Instruments Lecturer on the History of Science Department of the 
> History of Science, Harvard University Science Center 251c, 1 Oxford 
> Street, Cambridge, MA 02138
> Tel: 617-496-9542   |   Fax: 617-495-3344  |   sche...@fas.harvard.edu  
> |@SaraSchechner
> http://scholar.harvard.edu/saraschechner
> http://chsi.harvard.edu/
>  
>  
> ---
> 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: Golden Ratio and Sundials

[rodwall1...@gmail.com]

Hi Geoff and Frank,
My book also shows this.

By The Way, the book is one of a series called the Mathematical World by 
National Geographic. Where in Australia the 1st book. The Golden Ratio. The 
mathematical language of beauty. Was AUD $2. $2 to get you to purchase the 1st 
book. And then you may want to purchase the series of books. Of course they 
will not $2.

Regards,

Roderick Wall.

- Reply message -
From: "Frank King" 
To: "Geoff Thurston" 
Cc: "Michael Ossipoff" , "Sundial Mailing List" 

Subject: Golden Ratio and Sundials
Date: Sat, Jun 24, 2017 8:16 PM

Dear Geoff,

Many congratulations on your proof...

When I set the puzzle, I thought three things:

1. I am really setting this for Geoff to solve.

2. He will certainly solve it and will probably
be the first to publish.

3. His proof will either match mine or be more
elegant.

I was right on all three counts.  Your proof is
just what I had in mind.  Once you spot those
two triangles it is obvious that they are
similar and the rest comes out in the wash!

Very best wishes

Frank

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

Re: Golden Ratio and Sundials

[rodwall1...@gmail.com]

Hi all and thanks to everyone who responded to my questions. All very 
interesting.
John I have never see a spiral clock face. Very interesting thanks. Learn 
something every day.

That had me thinking. I think I have seen somewhere where there is a spiral 
sundial. Where a spot of light marked the time on the numbers on the spiral.

Wonder if it was a Golden Ratio spiral.

Have fun,

Roderick Wall.

- Reply message -
From: "John Carmichael" <jlcarmich...@comcast.net>
To: "'rodwall1...@gmail.com'" <rodwall1...@gmail.com>, <sundial@uni-koeln.de>
Subject: Golden Ratio and Sundials
Date: Sat, Jun 24, 2017 2:34 AM

Rod:



Do a goggle image search on “spiral clock face”.  A similar sundial face design 
could be made.   Time marks and numerals could be adjusted to be in the proper 
positions to be a functional sundial.







From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of 
rodwall1...@gmail.com
Sent: Wednesday, June 21, 2017 2:04 PM
To: sundial@uni-koeln.de
Subject: Golden Ratio and Sundials



Hi all,



I have been reading a book on the Golden Ratio which is 1.6180339887. It 
describes how the Golden Ratio describes how the spiral of a sea shell is 
produced. And how nature uses the Golden Ratio on the size of leaves etc.



Does anyone know if sundials have ever been produced useing the Golden Ratio. 
The Golden Ratio goes back in history so one wonders if it was ever applied to 
sundials.



The book describes that the short and long sizes of credit cards are close to 
being the Golden Ratio.



LongSide/ShortSide = Golden Ratio.



Regards,



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

Re: Golden Ratio and Sundials

[rodwall1...@gmail.com]

Hi Brooke,
Thanks, I can see that your information is from Da Book.

Roderick.

- Reply message -
From: "Brooke Clarke" 
To: "'Sundial Mailing List'" 
Subject: Golden Ratio and Sundials
Date: Thu, Jun 22, 2017 7:27 AM

Hi Roderick:

I also have a book on this number that makes the case that there is no such 
ratio.  For example if you look at a 
photograph of something where do you put the markers to make the measurement?

It's interesting that 4x5, 8x10 film cameras have aspect ratios of 1.25.  35mm 
film cameras (36 x 24mm) have a ratio of 
1.5 the same as most DSLR cameras, yet the most common printer paper aspect 
ratios are still 1.25 (4x5 or 8x10).  But 
you can get 4x6 or 8x12" paper for an aspect ratio of 1.5.  Note all of these 
are smaller than 1.618.

-- 
Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html

 Original Message 
> Hi all,
>
> I have been reading a book on the Golden Ratio which is 1.6180339887. It 
> describes how the Golden Ratio describes how 
> the spiral of a sea shell is produced. And how nature uses the Golden Ratio 
> on the size of leaves etc.
>
> Does anyone know if sundials have ever been produced useing the Golden Ratio. 
> The Golden Ratio goes back in history so 
> one wonders if it was ever applied to sundials.
>
> The book describes that the short and long sizes of credit cards are close to 
> being the Golden Ratio.
>
> LongSide/ShortSide = Golden Ratio.
>
> Regards,
>
> Roderick Wall.
>
>
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Golden Ratio and Sundials

[rodwall1...@gmail.com]

Hi all,
I have been reading a book on the Golden Ratio which is 1.6180339887. It 
describes how the Golden Ratio describes how the spiral of a sea shell is 
produced. And how nature uses the Golden Ratio on the size of leaves etc.

Does anyone know if sundials have ever been produced useing the Golden Ratio. 
The Golden Ratio goes back in history so one wonders if it was ever applied to 
sundials.

The book describes that the short and long sizes of credit cards are close to 
being the Golden Ratio.

LongSide/ShortSide = Golden Ratio.

Regards,

Roderick Wall.

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

Re: Brass or Bronze for Sundials.

[rodwall1...@gmail.com]

Thanks all for your response.
Is there a particular grade of bronze that is suitable for sundials. And why 
are they suitable.

I like the idea of stainless steel but think that bronze or brass is more 
suitable.

Thanks in advance,

Regards,

Roderick Wall.

- Reply message -
From: "tonylindi...@talktalk.net" <tonylindi...@talktalk.net>
To: <rodwall1...@gmail.com>, <sundial@uni-koeln.de>
Subject: Brass or Bronze for Sundials.
Date: Mon, Jun 5, 2017 7:34 PM

Hi Rod,
The advantages for me is that they look good and take a handsome patination if 
regularly cleaned and waxed with a conservators' product. (Details on request). 
 Corrosion is a main problem, perhaps summed up by

"I am a sundial...ordinary words
Cannot convey my thoughts on birds!"   Hilaire Belloc

.. and their corrosive droppings. :-(  I sometimes suspect that my local 
feathered friends feed on acidic epoxy glue! ;-)

Stainless steel (S316 grade) makes an excellent weatherproof dial if the 
surface is lightly textured to reveal a shadow and if you can find an 
etcher/engraver who will 'cut' it deeply enough.  My preferred surface 
treatment was a Random Orbital sander with a worn medium paper which MUST be in 
contact before switching ON then lifted away before switching OFF to avoid 
start/stop 'swirls'.  This tool is widely used on car body finishing.

Tony M.

P.S.  Now that I know that others can view my messages I have no need to read 
them myself.




----Original Message

From: rodwall1...@gmail.com

Date: 05/06/2017 1:58 

To: <sundial@uni-koeln.de>

Subj: Brass or Bronze for Sundials.




Hi all,
For a sundial that will be out in the weather. What is the 
advantage/disadvantage of using brass or bronze?
Regards,
Roderick Wall.
---
https://lists.uni-koeln.de/mailman/listinfo/sundial---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Brass or Bronze for Sundials.

[rodwall1...@gmail.com]

Hi all,
For a sundial that will be out in the weather. What is the 
advantage/disadvantage of using brass or bronze?

Regards,

Roderick Wall.

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

Mounting sundials. Method byTony Moss.

[rodwall1...@gmail.com]

Hi Tony,
Think you may has missed my request. For photos on how to securely mount a 
sundial. You did describe how to do this but photos would help. This was with 
reference to mounting a sundial on the John Smith memorial in Australia.

Kind regards,

Roderick Wall.

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

Mounting Sundials...securely

[rodwall1...@gmail.com]

Hi all,
In the Ranelagh Estate at Mount Eliza Victoria 3930 Australia. There is a 
memorial to John Thomas Smith in Ranelagh drive. The memorial was surmounted by 
a sundial. It was there as late as 2004. It was removed by unknown people 
several times and was replaced by the shire. But the shire eventually gave up 
as the sundial could not be adequately secured.

Question, does anyone know of a way to adequately secure a sundial on the 
following memorial?

http://monumentaustralia.org.au/themes/people/settlement/display/32753-john-thomas-smith

It is such a shame that we all can't enjoy a sundial. Without someone thinking 
that they should have it for themselves only.

Thanks,

Roderick Wall.

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

Re: Inquiry - Part 1

[rodwall1...@gmail.com]

Hi Steve,
Any chance of getting a copy of or where to get it.

I found a 1737 publication /Regle artificielle du temps /by Henry Sully, 
an English clockmaker in Paris and clockmaker to the Duc D'Orleans, 
which has fairly extensive instructions on how to regulate clocks using 
either a sundial or by observing transits of stars

Would be interesting to see how they did it.

Regards,

Roderick Wall.

- Reply message -
From: "Steve Lelievre" 
To: "Frank King" 
Cc: "sundial@uni-koeln.de" 
Subject: Inquiry - Part 1
Date: Fri, Apr 28, 2017 1:39 AM

Dear Frank,

You're right - the timeline casts doubt on the premise of the enquiry. 
Well spotted!

For anyone who's interested, here's a snippet from/Enclopaedia 
Britannica/ (7th ed.)

"The first [Equation Clock] was made about the year 1693 by Mr Joseph 
Williamson, an English artist then working for Mr Daniel Quare 
watchmaker in London, who sold it to go to Charles II King of Spain 
about the year 1699. It went 400 days with one winding and had two fixed 
and two movable circles for the hands to mark the time on : the former 
giving the hours and minutes of mean time; and the latter, which were 
concentric with the former, apparent time. [...] Father Alexandre, a 
Benedictine, had laid a project of this sort before the Academy of 
Sciences in 1698 which is mentioned in their Memoirs for 1725 but 
nothing of the kind seems to have been practised in France till a clock, 
the equation work of which scarcely differed from Williamson's, was made 
by Lebon in 1717. This was soon after followed by another by Leroy."

I found a 1737 publication /Regle artificielle du temps /by Henry Sully, 
an English clockmaker in Paris and clockmaker to the Duc D'Orleans, 
which has fairly extensive instructions on how to regulate clocks using 
either a sundial or by observing transits of stars,  and how to convert 
a mean time reading to solar time by use of Equation of Time tables. I 
didn't notice any mention of equation clocks when I looked through 
Sully's treatise, so I assume they remained rather rare even 20 years 
after Le Bon and Le Roy had introduced them.

Thanks to everyone who has responded to my enquiries.

Steve



On 2017-04-26 5:44 AM, Frank King wrote:
> Dear Steve,
>
> I have read the replies to your enquiry and I
> am not yet convinced by the responses to either
> Part 1 or Part 2!
>
> I'll restrict myself to Part 1, where it is
> asserted...
>
> ...that Louis XIV issued some kind of edict
> that all clocks manufactured in France were
> to be Equation Clocks (that is, clocks that
> showed solar time through a mechanical
> Equation of Time 'reversal' adjustment).
>
> One point of note is that Louis XIV reigned
> from 1643 to 1715 so this edict must have been
> sometime in those 72 years.
>
> Roderick Wall's reference...
>
> https://books.google.com.au/books?id=d1oUQAAJ=PA462=PA462=all+clo
> cks+manufactured+in+France+were+to+be+Equation+Clocks=bl=ih4yWalJ9E&
> sig=6u-sTxpfyTqZNPxRjfbAn7Q_ECk=en=X=0ahUKEwjW9oruqrbTAhVEGJQKHU-NDrs
> Q6AEIIzAD#v=onepage=all%20clocks%20manufactured%20in%20France%20were%20to%20b
> e%20Equation%20Clocks=false
>
> says on page 462...
>
> Equation clocks were first made in France,
> about the year 1717, by Le Bon and Le Roy.
>
> It seems unlikely that Louis XIV could have
> insisted on something that didn't exist in
> his time.
>
> As king, Louis XIV no doubt had up-market
> clocks in his palaces and he could simply
> have instructed his clock-keepers to set
> the clocks using a convenient sundial.
>
> The solar day typically differs from 24 modern
> hours by a small fraction of a minute and it
> is unlikely that the clocks early in his reign
> kept time to anything like that precision.
> Frequent setting to sundial time would have
> been required.
>
> When he upgraded to pendulum clocks he may
> have noticed that his clock-keepers had
> changed their procedures...
>
> I think the first EoT tables used for
> "correcting" clocks were published by
> Huygens in 1665 and better tables were
> published by Flamsteed about 7 years
> later.
>
> Enthusiastic clock-keepers may have used
> these tables and the king may not have
> approved.  The only edict that he need
> have issued would have been of the form:
>
>"Do not use the equation of time when
> setting the clocks."
>
> I know how to dig out ancient English Acts
> of Parliament but I do not know how to find
> old French edicts.
>
>   Please can someone nail down this edict?
>
> Until I can read this edict in 17th century
> French, I shall deem this to be another
> example of a much-repeated falsehood
> gaining widespread acceptance.
>
> Now to ponder part 2!
>
> Frank
>
> Frank H. King
> Cambridge, U.K.
>
>---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Inquiry - Part 2

[rodwall1...@gmail.com]

Hi all,
This link indicates when the telegraph was 1st perfected.

1837 Cook and Wheatstone in England.

http://www.persee.fr/doc/flux_1154-2721_1993_num_9_11_939

Regards,

Roderick Wall.

- Reply message -
From: "Frank King" 
To: "Steve Lelievre" 
Cc: "sundial@uni-koeln.de" 
Subject: Inquiry - Part 2
Date: Wed, Apr 26, 2017 10:46 PM

Dear Steve,

Part 2 of your enquiry asserted that...

...throughout the 19th century...
the French railways system used 
heliochronometers installed at each
station for daily calibration of station
clocks?

Again, this is a good story but I simply
cannot see why this would be true...

Just for a start, "throughout the 19th
century" cannot be right.  The railways
were not introduced to France until the
late 1820s.

High-quality French chronometers had been
around since the 1760s with Le Roy being
the leading maker.  The early railways
could have distributed time using these,
just as happened in England.

The Paris Observatory was never far behind
Greenwich in terms of tracking time and
could have provided definitive railway time
in France.

In England, the first railway to adopt the
electric telegraph was the Great Western
Railway in 1839 and this provided another
way of distributing time.

Why would the French railways have used
heliochronometers?

That said, it is not hard to find references
to this practice.  For example, in "Sundials:
History, Theory and Practice" by Rene R.J. Rohr.
Take a look at:

https://books.google.co.uk/books?isbn=0486151700

On page 16 we see he writes:

...this instrument [heliochronometer]
was used into the twentieth century by
some networks of the French railways
for uniformity in the setting of the
station clocks.

I can just about believe that an eccentric
station master might have set the station
clock via a heliochronometer but train
dispatchers and signalmen and others
who actually implemented the timetable
would have had company watches in their
waistcoats.  These were set by more
reliable means.

On page 17 you see a drawing of a 
"heliochronometer" which is just a
simple semi-equatorial dial with
no obvious means for longitude 
correction never mind EoT.

This is not my idea of a heliochronometer.

Please can someone find a contemporary
account of a French stationmaster
describing his use of a heliochronometer.

Until I can read this in French, I shall
deem the account to be yet another example
of a much-repeated falsehood that has gained
widespread acceptance.

I should be delighted to be proved wrong
on both matters!

Frank

Frank H. King
Cambridge, U.K.



---
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Re: Inquiry - Part 2

[rodwall1...@gmail.com]

Hi Frank and Steve,
This link is interesting on early telegraph systems in France.

http://www.bbc.com/news/magazine-22909590

Roderick Wall.

- Reply message -
From: "Frank King" 
To: "Steve Lelievre" 
Cc: "sundial@uni-koeln.de" 
Subject: Inquiry - Part 2
Date: Wed, Apr 26, 2017 10:46 PM

Dear Steve,

Part 2 of your enquiry asserted that...

...throughout the 19th century...
the French railways system used 
heliochronometers installed at each
station for daily calibration of station
clocks?

Again, this is a good story but I simply
cannot see why this would be true...

Just for a start, "throughout the 19th
century" cannot be right.  The railways
were not introduced to France until the
late 1820s.

High-quality French chronometers had been
around since the 1760s with Le Roy being
the leading maker.  The early railways
could have distributed time using these,
just as happened in England.

The Paris Observatory was never far behind
Greenwich in terms of tracking time and
could have provided definitive railway time
in France.

In England, the first railway to adopt the
electric telegraph was the Great Western
Railway in 1839 and this provided another
way of distributing time.

Why would the French railways have used
heliochronometers?

That said, it is not hard to find references
to this practice.  For example, in "Sundials:
History, Theory and Practice" by Rene R.J. Rohr.
Take a look at:

https://books.google.co.uk/books?isbn=0486151700

On page 16 we see he writes:

...this instrument [heliochronometer]
was used into the twentieth century by
some networks of the French railways
for uniformity in the setting of the
station clocks.

I can just about believe that an eccentric
station master might have set the station
clock via a heliochronometer but train
dispatchers and signalmen and others
who actually implemented the timetable
would have had company watches in their
waistcoats.  These were set by more
reliable means.

On page 17 you see a drawing of a 
"heliochronometer" which is just a
simple semi-equatorial dial with
no obvious means for longitude 
correction never mind EoT.

This is not my idea of a heliochronometer.

Please can someone find a contemporary
account of a French stationmaster
describing his use of a heliochronometer.

Until I can read this in French, I shall
deem the account to be yet another example
of a much-repeated falsehood that has gained
widespread acceptance.

I should be delighted to be proved wrong
on both matters!

Frank

Frank H. King
Cambridge, U.K.



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

Re: Inquiry

[rodwall1...@gmail.com]

Hi Steve,
Here is a link which has some interesting history information about Equation 
Clocks. 

Roderick Wall.

https://books.google.com.au/books?id=d1oUQAAJ=PA462=PA462=all+clocks+manufactured+in+France+were+to+be+Equation+Clocks=bl=ih4yWalJ9E=6u-sTxpfyTqZNPxRjfbAn7Q_ECk=en=X=0ahUKEwjW9oruqrbTAhVEGJQKHU-NDrsQ6AEIIzAD#v=onepage=all%20clocks%20manufactured%20in%20France%20were%20to%20be%20Equation%20Clocks=false

- Reply message -
From: "Steve Lelievre" 
To: "sundial@uni-koeln.de" 
Subject: Inquiry
Date: Sat, Apr 22, 2017 5:44 AM

Hi,

I've got a two part inquiry from a third party:

1. Is it true that Louis XIV issued some kind of edict that all clocks 
manufactured in France were to be Equation Clocks (that is, clocks that 
showed solar time through a mechanical Equation of Time 'reversal' 
adjustment). References sought.

2. Can anyone confirm that throughout the 19th centuary (and perhaps 
into the early 20th centuary?), the French railways system used 
heliochronometers installed at each station for daily calibration of 
station clocks? Again, references sought.

Thanks,
Steve


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

Re: Time question on GPS TIME and leap second.

[rodwall1...@gmail.com]

Hi Brooke,
The radio controlled clock that you described that uses  WWVB is very good. If 
you live in Canada, America or Mexico.

But I don't think it would work in Australia or some other parts in the world.

Where the GPS signals can be received anywhere. 

For the Silicon Chip GPS controlled clock. The firmware is written in the C 
programming language. And is available if you want to make it work the way you 
want it to.

Have fun,

Roderick Wall.

- Reply message -
From: "Brooke Clarke" <bro...@pacific.net>
To: "rodwall1...@gmail.com" <rodwall1...@gmail.com>, "sundial list" 
<sundial@uni-koeln.de>
Subject: Time question on GPS TIME and leap second.
Date: Fri, Feb 3, 2017 6:06 AM

Hi Rod:

OK, that allows you to set the clock., but it's not a stand alone self setting 
clock.
I was disappointed with the Heathkit GC-1000 when I found that it was off by an 
hour at the changes of daylight savings 
in displaying my local time.  (It changed time when the transmitter in Colorado 
changed it's time rather than when it 
should.)  As far as I know that was never fixed.

GPS does not know about the date or daylight savings, but does have a way to 
get to UTC by using the accumulated offset 
between GPS and UTC.

So the only way to have an accurate and self setting clock is to make use of a 
"time" station like WWV or WWVB.  I've 
only heard of one clock model that makes use of the phase modulation that's 
been on WWVB for many years and it's the La 
Crosse 404-1235UA-SS.

-- 
Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html

 Original Message 
> Hi Brooke,
>
> True, GPS doesn't know about daylight saving.
>
> To set the clock up after building it. You use a RS232 Com terminal program, 
> to talk to the clock driver 
> microprocessor. And set up the month and which Sunday daylight saving starts 
> and finishes.
>
> You need to:
> Set your time zone.
> Daylight saving ON or OFF.
> Start daylight saving month.
> Start daylight saving Sunday.
> End daylight saving month.
> End daylight saving Sunday.
> Set clock pulse mSeconds.
> Set GPS update (hours).
>
> Q = quit.
>
> Command:_
>
> The firmware is written in the C language. Source code can be downloaded and 
> you can play around with it if you want.
>
> Article also gives a web link for the free Hi-Tech C Compiler.
>
> I'm waiting to see if a local electronic supplier produces a kit of parts for 
> it.
>
> Looks like fun,
>
> Roderick Wall.
>
> - Reply message -
> From: "Brooke Clarke" <bro...@pacific.net>
> To: "sundial list" <sundial@uni-koeln.de>
> Subject: Time question on GPS TIME and leap second.
> Date: Thu, Feb 2, 2017 9:26 AM
>
> Hi Roderick:
>
> GPS knows about neither daylight savings nor the date.
> The article mentions "understands the rules of daylight saving (DST)" which 
> are a political thing so this will only work
> until the rules change.
> This happened to VCR players and after the rules change they are always wrong.
> The only time source that knows about these things are the time stations, 
> like WWV & WWVB.
> http://www.prc68.com/I/timefreq.shtml#RSL
>
> -- 
> Have Fun,
>
> Brooke Clarke
> http://www.PRC68.com
> http://www.end2partygovernment.com/2012Issues.html
>
>  Original Message 
> > A recent article on the GPS analog clock driver. A better description;
> >
> >http://archive.siliconchip.com.au/cms/A_92/article.html
> >
> > Roderick Wall.
> >
> > - Reply message -
> > From: "Richard Langley" <l...@unb.ca>
> > To: "Brooke Clarke" <bro...@pacific.net>, "sundial list" 
> > <sundial@uni-koeln.de>
> > Subject: Time question on GPS TIME and leap second.
> > Date: Tue, Jan 31, 2017 10:33 AM
> >
> > "This causes problems for GPS receivers that are more than a few years old 
> > since they have no idea what year it is."
> >
> >
> > Not quite true. One of the continuously operating receivers at UNB is more 
> > than 15 years old. Please see:
> >
> >http://gauss2.gge.unb.ca/gpsworld/gpsworld.november98.pdf​ 
> <http://gauss2.gge.unb.ca/gpsworld/gpsworld.november98.pdf%E2%80%8B>  
> > <http://gauss2.gge.unb.ca/gpsworld/gpsworld.november98.pdf%E2%80%8B>
> >
> >
> > -- Richard Langley
> >
> >
> > -
> > | Richard B. LangleyE-mail: l...@unb.ca 
> > |
> > | Geodetic Research Labor

Re: Time question on GPS TIME and leap second.

[rodwall1...@gmail.com]

Hi Brooke,
True, GPS doesn't know about daylight saving.

To set the clock up after building it. You use a RS232 Com terminal program, to 
talk to the clock driver microprocessor. And set up the month and which Sunday 
daylight saving starts and finishes.

You need to:
Set your time zone.
Daylight saving ON or OFF.
Start daylight saving month.
Start daylight saving Sunday.
End daylight saving month.
End daylight saving Sunday.
Set clock pulse mSeconds.
Set GPS update (hours).

Q = quit.

Command:_

The firmware is written in the C language. Source code can be downloaded and 
you can play around with it if you want.

Article also gives a web link for the free Hi-Tech C Compiler.

I'm waiting to see if a local electronic supplier produces a kit of parts for 
it.

Looks like fun,

Roderick Wall.

- Reply message -
From: "Brooke Clarke" 
To: "sundial list" 
Subject: Time question on GPS TIME and leap second.
Date: Thu, Feb 2, 2017 9:26 AM

Hi Roderick:

GPS knows about neither daylight savings nor the date.
The article mentions "understands the rules of daylight saving (DST)" which are 
a political thing so this will only work 
until the rules change.
This happened to VCR players and after the rules change they are always wrong.
The only time source that knows about these things are the time stations, like 
WWV & WWVB.
http://www.prc68.com/I/timefreq.shtml#RSL

-- 
Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html

 Original Message 
> A recent article on the GPS analog clock driver. A better description;
>
> http://archive.siliconchip.com.au/cms/A_92/article.html
>
> Roderick Wall.
>
> - Reply message -
> From: "Richard Langley" 
> To: "Brooke Clarke" , "sundial list" 
> 
> Subject: Time question on GPS TIME and leap second.
> Date: Tue, Jan 31, 2017 10:33 AM
>
> "This causes problems for GPS receivers that are more than a few years old 
> since they have no idea what year it is."
>
>
> Not quite true. One of the continuously operating receivers at UNB is more 
> than 15 years old. Please see:
>
> http://gauss2.gge.unb.ca/gpsworld/gpsworld.november98.pdf​ 
> 
>
>
> -- 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/
>|
> -
> 
> From: sundial  on behalf of Brooke Clarke 
> 
> Sent: Monday, January 30, 2017 4:29 PM
> To: sundial list
> Subject: Re: Time question on GPS TIME and leap second.
>
> Hi Roderick:
>
> GPS time is continuous, that's to say there are no leap seconds or other 
> changes to it since it started.  It uses a 10 bit binary week counter so the 
> week number rolls over after 1024 weeks.  This causes problems for GPS 
> receivers that are more than a few years old since they have no idea what 
> year it is.
> The total number of seconds offset from UTC is transmitted separately so that 
> a GPS receiver can display either GPS time or UTC.
> Note that the time and position are independent from the year.
>
> http://www.prc68.com/I/Trimpack.shtml#WkRlvr
>
> --
> Have Fun,
>
> Brooke Clarke
> http://www.PRC68.com
> http://www.end2partygovernment.com/2012Issues.html
>
>
>  Original Message 
> Hi all,
>
> Was just listening to the CrowdScience on time. Thanks to whoever posted the 
> link to it.
>
> CrowdScience indicated that a leap second was not added for the GPS. They 
> also indicated that the GPS gives us UTC time.
>
> Question:
> The UTC time that the GPS gives. Does that have the leap second added?
>
> Thanks,
>
> Regards,
>
> Roderick Wall.
>
> - Reply message -
> From: "Michael Ossipoff" 
> 
> To: "Robert Kellogg" 
> Cc: "sundial list" 
> Subject: Why we should reform the Calendar
> Date: Mon, Jan 30, 2017 8:00 AM
>
>
> On Sun, Jan 29, 2017 at 2:41 PM, Robert Kellogg 
> 

Re: Time question on GPS TIME and leap second.

[rodwall1...@gmail.com]

A recent article on the GPS analog clock driver. A better description;
http://archive.siliconchip.com.au/cms/A_92/article.html

Roderick Wall.

- Reply message -
From: "Richard Langley" 
To: "Brooke Clarke" , "sundial list" 
Subject: Time question on GPS TIME and leap second.
Date: Tue, Jan 31, 2017 10:33 AM

"This causes problems for GPS receivers that are more than a few years old 
since they have no idea what year it is."


Not quite true. One of the continuously operating receivers at UNB is more than 
15 years old. Please see:

http://gauss2.gge.unb.ca/gpsworld/gpsworld.november98.pdf​


-- 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/
   |
-

From: sundial  on behalf of Brooke Clarke 

Sent: Monday, January 30, 2017 4:29 PM
To: sundial list
Subject: Re: Time question on GPS TIME and leap second.

Hi Roderick:

GPS time is continuous, that's to say there are no leap seconds or other 
changes to it since it started.  It uses a 10 bit binary week counter so the 
week number rolls over after 1024 weeks.  This causes problems for GPS 
receivers that are more than a few years old since they have no idea what year 
it is.
The total number of seconds offset from UTC is transmitted separately so that a 
GPS receiver can display either GPS time or UTC.
Note that the time and position are independent from the year.

http://www.prc68.com/I/Trimpack.shtml#WkRlvr

--
Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html


 Original Message 
Hi all,

Was just listening to the CrowdScience on time. Thanks to whoever posted the 
link to it.

CrowdScience indicated that a leap second was not added for the GPS. They also 
indicated that the GPS gives us UTC time.

Question:
The UTC time that the GPS gives. Does that have the leap second added?

Thanks,

Regards,

Roderick Wall.

- Reply message -
From: "Michael Ossipoff" 
To: "Robert Kellogg" 
Cc: "sundial list" 
Subject: Why we should reform the Calendar
Date: Mon, Jan 30, 2017 8:00 AM


On Sun, Jan 29, 2017 at 2:41 PM, Robert Kellogg 

wrote:

> Michael goes off looking for the ideal tropical year


There isn't an "ideal tropical year", but, as a choice for a
leapyear-rule's mean-year, the length of the mean tropical year (MTY) is
best for year-round reduction of longterm calendar-drift.  ...and the
average of the lengths of the March & September Equinox tropical years
(I'll call that the Average Equinox Year (AEY) ) is a compromise between
the vernal equinoxes of the North & the South.


> , perhaps ignoring effects of the earth's nutations.
>

Of course. The nutations are small in amplitude & period. They aren't part
of calendar rules. The mean equinox (nutations averaged-out) is the one
that is meant when the equinox is spoken of with regard to calendars.



> I'll still take the one of 1900, most importantly because it defines the
> SI second.


The SI second was defined as 1/86,400 of a mean solar day, for some year in
the early 19th century. I don't remember exactly what year that was. 1820?
1840? 1850?

Evidently it isn't practical to update the length of the SI second, but
that doesn't mean that calendars have to be based on the ephemeris day, or
atomic day, consisting of 86,400 SI seconds, when that's known to be
different from today's mean solar day.

That's why I suggest 365.24217 instead of 365.24219 for the length of the
mean tropical year (MTYI. It makes sense to base a calendar leap-year
rule's mean-year on the actual length of a tropical-year (whichever one we
want to use) on the length of that tropical year in* today's* mean days.


>
>
> So, contemplating changing the year is non trivial.


Evidently there must be some reason why it would be impractical to update
the length of the SI second. But it isn't necessary to call a MTY 365.24219
days, when it's really 365.24217 mean days 

Re: Time question on GPS TIME and leap second.

[rodwall1...@gmail.com]

Thanks to all who replied to my questions about the time on GPS.
The reason I asked about the leap second. Is if the following analog clock GPS 
driver included the leap second correction.

Yes it would.

http://www.altronics.com.au/p/k1129-gps-synchronised-clock-kit/

It also corrects it for daylight saving.

Thanks all,

Roderick Wall.

- Reply message -
From: "Brooke Clarke" 
To: "sundial list" 
Subject: Time question on GPS TIME and leap second.
Date: Tue, Jan 31, 2017 7:29 AM

Hi Roderick:

GPS time is continuous, that's to say there are no leap seconds or other 
changes to it since it started.  It uses a 10 
bit binary week counter so the week number rolls over after 1024 weeks.  This 
causes problems for GPS receivers that are 
more than a few years old since they have no idea what year it is.
The total number of seconds offset from UTC is transmitted separately so that a 
GPS receiver can display either GPS time 
or UTC.
Note that the time and position are independent from the year.

http://www.prc68.com/I/Trimpack.shtml#WkRlvr

-- 
Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html

 Original Message 
> Hi all,
>
> Was just listening to the CrowdScience on time. Thanks to whoever posted the 
> link to it.
>
> CrowdScience indicated that a leap second was not added for the GPS. They 
> also indicated that the GPS gives us UTC time.
>
> Question:
> The UTC time that the GPS gives. Does that have the leap second added?
>
> Thanks,
>
> Regards,
>
> Roderick Wall.
>
> - Reply message -
> From: "Michael Ossipoff" 
> To: "Robert Kellogg" 
> Cc: "sundial list" 
> Subject: Why we should reform the Calendar
> Date: Mon, Jan 30, 2017 8:00 AM
>
> On Sun, Jan 29, 2017 at 2:41 PM, Robert Kellogg 
> wrote:
>
> > Michael goes off looking for the ideal tropical year
>
>
> There isn't an "ideal tropical year", but, as a choice for a
> leapyear-rule's mean-year, the length of the mean tropical year (MTY) is
> best for year-round reduction of longterm calendar-drift.  ...and the
> average of the lengths of the March & September Equinox tropical years
> (I'll call that the Average Equinox Year (AEY) ) is a compromise between
> the vernal equinoxes of the North & the South.
>
>
> > , perhaps ignoring effects of the earth's nutations.
> >
>
> Of course. The nutations are small in amplitude & period. They aren't part
> of calendar rules. The mean equinox (nutations averaged-out) is the one
> that is meant when the equinox is spoken of with regard to calendars.
>
>
>
> > I'll still take the one of 1900, most importantly because it defines the
> > SI second.
>
>
> The SI second was defined as 1/86,400 of a mean solar day, for some year in
> the early 19th century. I don't remember exactly what year that was. 1820?
> 1840? 1850?
>
> Evidently it isn't practical to update the length of the SI second, but
> that doesn't mean that calendars have to be based on the ephemeris day, or
> atomic day, consisting of 86,400 SI seconds, when that's known to be
> different from today's mean solar day.
>
> That's why I suggest 365.24217 instead of 365.24219 for the length of the
> mean tropical year (MTYI. It makes sense to base a calendar leap-year
> rule's mean-year on the actual length of a tropical-year (whichever one we
> want to use) on the length of that tropical year in* today's* mean days.
>
>
> >
> >
> > So, contemplating changing the year is non trivial.
>
>
> Evidently there must be some reason why it would be impractical to update
> the length of the SI second. But it isn't necessary to call a MTY 365.24219
> days, when it's really 365.24217 mean days long.   ...for the purposes of a
> calendar leapyear rule. There's inevitable inaccuracy due to rounding-off,
> and due to gradual change in the lengths of all the tropical years,
> including the MTY. But that doesn't mean we have to intentionally add
> avoidable error.
>
>
>
> > Contemplating decoupling UTC from the rotation of the earth (ie necessity
> > of being within .9 sec of UT1) likewise has significant consequences.
> > Let's let the IAU chart the future of time.
>
>
> Sure, but it isn't necessary to base a calendar on a day that isn't today's
> mean solar day.
>
> Michael Ossipoff
>
>
>
>
>
> > Dennis and Ken, if you're listening to this discussion, please chime in.
> >
> >
> > On 1/29/2017 12:27 PM, sundial-requ...@uni-koeln.de wrote:
> >
> >> Send sundial mailing list submissions to
> >> sundial@uni-koeln.de
> >>
> >> To subscribe or unsubscribe via the World Wide Web, visit
> >>https://lists.uni-koeln.de/mailman/listinfo/sundial
> >> or, via email, send a message with subject or body 'help' to
> >> sundial-requ...@uni-koeln.de
> >>
> >> You can reach the person managing the list at
> >> sundial-ow...@uni-koeln.de
> >>
> >> When 

Time question on GPS TIME and leap second.

[rodwall1...@gmail.com]

Hi all,
Was just listening to the CrowdScience on time. Thanks to whoever posted the 
link to it.

CrowdScience indicated that a leap second was not added for the GPS. They also 
indicated that the GPS gives us UTC time. 

Question:
The UTC time that the GPS gives. Does that have the leap second added?

Thanks,

Regards,

Roderick Wall.

- Reply message -
From: "Michael Ossipoff" 
To: "Robert Kellogg" 
Cc: "sundial list" 
Subject: Why we should reform the Calendar
Date: Mon, Jan 30, 2017 8:00 AM

On Sun, Jan 29, 2017 at 2:41 PM, Robert Kellogg 
wrote:

> Michael goes off looking for the ideal tropical year


There isn't an "ideal tropical year", but, as a choice for a
leapyear-rule's mean-year, the length of the mean tropical year (MTY) is
best for year-round reduction of longterm calendar-drift.  ...and the
average of the lengths of the March & September Equinox tropical years
(I'll call that the Average Equinox Year (AEY) ) is a compromise between
the vernal equinoxes of the North & the South.


> , perhaps ignoring effects of the earth's nutations.
>

Of course. The nutations are small in amplitude & period. They aren't part
of calendar rules. The mean equinox (nutations averaged-out) is the one
that is meant when the equinox is spoken of with regard to calendars.



> I'll still take the one of 1900, most importantly because it defines the
> SI second.


The SI second was defined as 1/86,400 of a mean solar day, for some year in
the early 19th century. I don't remember exactly what year that was. 1820?
1840? 1850?

Evidently it isn't practical to update the length of the SI second, but
that doesn't mean that calendars have to be based on the ephemeris day, or
atomic day, consisting of 86,400 SI seconds, when that's known to be
different from today's mean solar day.

That's why I suggest 365.24217 instead of 365.24219 for the length of the
mean tropical year (MTYI. It makes sense to base a calendar leap-year
rule's mean-year on the actual length of a tropical-year (whichever one we
want to use) on the length of that tropical year in* today's* mean days.


>
>
> So, contemplating changing the year is non trivial.


Evidently there must be some reason why it would be impractical to update
the length of the SI second. But it isn't necessary to call a MTY 365.24219
days, when it's really 365.24217 mean days long.   ...for the purposes of a
calendar leapyear rule. There's inevitable inaccuracy due to rounding-off,
and due to gradual change in the lengths of all the tropical years,
including the MTY. But that doesn't mean we have to intentionally add
avoidable error.



> Contemplating decoupling UTC from the rotation of the earth (ie necessity
> of being within .9 sec of UT1) likewise has significant consequences.
> Let's let the IAU chart the future of time.


Sure, but it isn't necessary to base a calendar on a day that isn't today's
mean solar day.

Michael Ossipoff





> Dennis and Ken, if you're listening to this discussion, please chime in.
>
>
> On 1/29/2017 12:27 PM, sundial-requ...@uni-koeln.de wrote:
>
>> Send sundial mailing list submissions to
>> sundial@uni-koeln.de
>>
>> To subscribe or unsubscribe via the World Wide Web, visit
>> https://lists.uni-koeln.de/mailman/listinfo/sundial
>> or, via email, send a message with subject or body 'help' to
>> sundial-requ...@uni-koeln.de
>>
>> You can reach the person managing the list at
>> sundial-ow...@uni-koeln.de
>>
>> When replying, please edit your Subject line so it is more specific
>> than "Re: Contents of sundial digest..."
>>
>>
>> Today's Topics:
>>
>> 1. Re: Why we should reform the Calendar (Michael Ossipoff)
>>
>>
>> --
>>
>> Message: 1
>> Date: Sun, 29 Jan 2017 12:27:56 -0500
>> From: Michael Ossipoff 
>> To: Dan-George Uza 
>> Cc: sundial list 
>> Subject: Re: Why we should reform the Calendar
>> Message-ID:
>> > gmail.com>
>> Content-Type: text/plain; charset="utf-8"
>>
>>
>> Here are two (unimportant) objections to the Nearest-Monday year-start
>> system:
>>
>> 1. It's based on the Gregorian leapyear-rule, meaning that it isn't
>> self-contained & free-standing. Mostly an aesthetic objection, and I don't
>> consider it important.
>>
>> 2. It inherits certain properties of the Gregorian Calendar, which could
>> otherwise be adjustable, choose-able. This, too, I consider only an
>> aesthetic objection.
>>
>> Here are the properties that I refer to:
>>
>> The Gregorian leapyear-rule was designed to minimize the date's variation
>> at the (northern) Vernal Equinox, the March equinox.
>>
>> We often hear it said that the mean tropical year is the time from one
>> March equinox to the next. Not so. That's 

Re: An interesting piece of timekeeping

[rodwall1...@gmail.com]

Hi Jack,
Is this for Android? I couldn't find it.

Roderick Wall.

- Reply message -
From: "Jack Aubert" 
To: "'David Patte ₯'" , 
Subject: An interesting piece of timekeeping
Date: Wed, Jan 18, 2017 10:17 AM

The smartphone app has been written.  

Look for Chronometer by Emerald Sequoia.  You can easily spend hours exploring 
it.  It consists of fifteen different virtual watches, each one offering a 
different set of temporal and astronomical features.



Jack Aubert



From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of David Patte ?
Sent: Monday, January 16, 2017 10:11 PM
To: sundial@uni-koeln.de
Subject: Re: An interesting piece of timekeeping



True, but if I can get 125 sponsors of $400 each I can write you a smartphone 
app that has all the same features, looks similiar, and is 10 times more 
accurate - and it will adjust to your local timezone and labelling in 10 
languages to boot :)



2017-01-16 21:42, J. Tallman wrote:

It is not a sundial, but interesting nonetheless:

http://www.ablogtowatch.com/vacheron-constantin-les-cabinotiers-celestia-astronomical-grand-complication-3600-watch/

It is quite a feast for the eyes, and the mind...and if you have a spare 
million lying around, it could be yours!



Best, 

Jim Tallman
Artisan Industrials

www.artisanindustrials.com   
www.spectrasundial.com   
jtall...@artisanindustrials.com   
513-253-5497






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






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

Re: Quick Sundial Quiz - What's the matter with this dial? (Tower Bridge Equatorial)

[rodwall1...@gmail.com]

Hi Ian 
Very interesting story. The equatorial Tower Dial is a great sundial. 

Regards,

Roderick Wall.

- Reply message -
From: "Ian Maddocks" 
To: "sundial@uni-koeln.de" 
Subject: Quick Sundial Quiz - What's the matter with this dial? (Tower Bridge 
Equatorial)
Date: Fri, Dec 30, 2016 8:06 AM

hi folks

Here's your quick Christmas quiz - what is wrong with the sundial in the middle 
of the attached screengrab from Instagram #sundial?
It's the famous equatorial dial near Tower Bridge in London

Answer below.

v
v
v
v
v
v
v
v
v
v
v
v
v
v
v

The answer is that it's NOT actually the famous equatorial in London by Wendy 
Taylor but a copy in Shanghai, China.

I regularly trawl through Instagram #sundial 
(https://www.instagram.com/explore/tags/sundial/)  looking for new dials we 
haven't recorded in the BSS Register.   Back in September I saw the dial as you 
see it in the screen grab.  "It's the dial by Tower Bridge", I thought, "been 
there, seen that" but something about the photo processing ("nice" HDR, ie not 
over-done to my tastes) made me click through.   "But hang on those aren't the 
warehouses on the south side of the Thames , they're skyscrapers, it's tagged 
Shanghai !"   To see the original posting click 
https://www.instagram.com/p/BJ7UULOjxhs/?taken-by=gwctoo  , though I originally 
saw it 3 hours after it was posted when there were no comments.

I contacted Wendy Taylor via her website who confirmed it wasn't an official 
copy.  I managed to find its location and she started to work out what could be 
done about it.

Although they don't have StreetView in China there are some privately uploaded 
photospheres on Google Maps.The dial can be seen on the banks of the 
Huangpu River in the following photosphere (yes it's all one link) 
https://www.google.co.uk/maps/@31.2289389,121.5018597,3a,75.1y,125.54h,87.11t/data=!3m8!1e1!3m6!1s-3srhU91AL7E%2FV0MHA9iTjeI%2FDDY%2FpbHLMS1yqpAywGmRoyiLM5U87B5eLItmACLIB!2e4!3e11!6s%2F%2Flh3.googleusercontent.com%2F-3srhU91AL7E%2FV0MHA9iTjeI%2FDDY%2FpbHLMS1yqpAywGmRoyiLM5U87B5eLItmACLIB%2Fw203-h101-n-k-no%2F!7i8704!8i4352

Anyway I had forgotten about all it this but Wendy has just been in touch with 
the end to the story   At the end of November the story was run in The 
Independent UK newspaper.Second British artist accuses China of copying 
work after statue 'identical' to London sculpture spotted in Shanghai :   
http://www.independent.co.uk/arts-entertainment/art/china-copies-sculpture-british-wendy-taylor-timepiece-tower-bridge-london-shanghai-anish-kapoor-a7441076.html
then just four days later   Chinese authorities destroy Shanghai sculpture 
exposed as copy of British artist's iconic London work : 
http://www.independent.co.uk/arts-entertainment/art/china-copy-art-sculpture-shanghai-london-wendy-taylor-timepiece-tower-bridge-sundial-destroyed-a7448326.html
It also was mentioned in the Shanghai Daily 'Wonderful news' for UK 
sculptor   
http://www.shanghaidaily.com/metro/society/Wonderful-news-for-UK-sculptor/shdaily.shtml
and has been picked up by other media , see  
https://www.google.co.uk/#q=wendy+taylor+shanghai+sundial

Wishing you all a Happy New Year

Ian Maddocks

Chester, UK
53°11'50"N  2°52'41"W---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Equation of time on a Android Smart Watch

[rodwall1...@gmail.com]

Hi Gian,
Thanks for trying and testing the Equation of Time face for Smart Watches. Will 
be interesting to see how it goes.

Even though you have been beaten in producing a watch face. Do still push ahead 
with your own version. As there is enough room for another maybe more 
interesting  Equation of Time face. The market is worldwide.

Thanks,

Regards,

Roderick Wall.

- Reply message -
From: "Gian Casalegno" <gian.casale...@gmail.com>
To: "sundial" <sundial@uni-koeln.de>
Subject: Equation of time on a Android Smart Watch
Date: Sun, Dec 18, 2016 1:58 AM

Hi,
I have recently purchased a smartwatch with the idea of developing some
gnomonic features for Android Wear.
Now I see that I have been beaten :-(

Anyway I have just tried to download this "Equation of Time" app but
unfortunately it failed.
I have tried several times with no success, even if my Moto 360 smartwatch
is said to be fully compatible.

I have then sent an email to the app developers and I am now waiting for
some help.
I will keep you informed.

Ciao.
Gian


2016-12-17 1:34 GMT+01:00 rodwall1...@gmail.com <rodwall1...@gmail.com>:

> Hi all,
>
> Some time ago there was some discussion on Equation of time watches that
> cost $60,000 plus. Much too much for my pocket.
>
> Someone I can't remembered who. Indicated that it would be possible to
> have The Equation of time on a Android Smart Watch. But they couldn't find
> one.
>
> I thought that if there was a Equation of time for a Android Smart Watch.
> I would consider purchasing a Smart Watch. So I went to Google play and
> found what I thought was a nice watch face. And sent them a email
> suggesting that they might like to produce one for the Equation of time.
>
> They thought that it was a good idea and produced one as in the link below.
>
> The problem is I don't have a Android Smart Watch to see if it works.
>
> Maybe someone with a Android Smart Watch may like to try it and report
> back to the group as to how good it is. Cost is $1.39.
>
> https://play.google.com/store/apps/details?id=com.cga.time.equation
>
> Hoping that it works,
>
> Roderick Wall.
>
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
>---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Equation of time on a Android Smart Watch

[rodwall1...@gmail.com]

Hi all,
Some time ago there was some discussion on Equation of time watches that cost 
$60,000 plus. Much too much for my pocket.

Someone I can't remembered who. Indicated that it would be possible to have The 
Equation of time on a Android Smart Watch. But they couldn't find one.

I thought that if there was a Equation of time for a Android Smart Watch. I 
would consider purchasing a Smart Watch. So I went to Google play and found 
what I thought was a nice watch face. And sent them a email suggesting that 
they might like to produce one for the Equation of time.

They thought that it was a good idea and produced one as in the link below.

The problem is I don't have a Android Smart Watch to see if it works.

Maybe someone with a Android Smart Watch may like to try it and report back to 
the group as to how good it is. Cost is $1.39.

https://play.google.com/store/apps/details?id=com.cga.time.equation

Hoping that it works,

Roderick Wall.

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

Re: Two EOT watch movements

[rodwall1...@gmail.com]

Hi Bob,
There are some great equation of time watches in your links. I liked the

Audemars Piguet Royal Oak Equation of Time watch.
I wonder if the screen resolution of the smart watch. Would be high enough to 
display the fine details that would be required for tha above EOT watch?

And how long it will be before someone produces a Android application for a EOT 
watch. If someone does. I'll purchase a Smart watch.

Thanks for your links,

Roderick Wall.

- Reply message -
From: "Robert Terwilliger" 
To: 
Subject: Two EOT watch movements
Date: Mon, Oct 10, 2016 8:16 AM

A link to a Breguet page which includes two movements with the "Kidney
piece" which is an EOT graph realized on a circle. It turns once a year.  



http://www.breguet.com/en/history/inventions/equation-time



Some more equation watches:



http://iwmagazine.com/news-and-now/20160225/five-equation-of-time-watches/



A page listing the EOT as among the Top Five Useless Watch Complications



http://www.ablogtowatch.com/top-five-useless-watch-complications/



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

Re: Longcase Clock with Equation of TIme

[rodwall1...@gmail.com]

Hi Ian,
Thanks, never thought about smartwatch applications. Looks like I'll have to 
purchase a smartwatch for me to have a watch with the equation of time. But 
I'll have to wait until someone produces a application with a dial that has the 
EOT.

I notice that one of the android smartwatch application producers will add your 
watch if you tell them what it is. Maybe we should ask them to do one of the 
$30,000 EOT watches. That would be a lot cheaper.

Thanks,

Regards,

Roderick Wall.

- Reply message -
From: "Ian Maddocks" <ian_maddo...@hotmail.com>
To: "Willy Leenders" <willy.leend...@telenet.be>, "Sundial list" 
<sundial@uni-koeln.de>
Subject: Longcase Clock with Equation of TIme
Date: Sun, Oct 9, 2016 7:40 AM

hi Willy


As is the answer to so many things these days...  There's an app for that

If you have a smart watch you can create your own watch face as you like it 
with underlying code

For example

https://play.google.com/store/search?q=watchmaker=apps=en

shows all the watch-face making apps for android smart watches

I only found one reference to EoT in the G+ forum for the first (WatchMaker) app
(The e-watch was a recreation of a two sided real watch with EoT but they 
didnt' seem to have replicated the second side that had the EoT)
so there's a gap in the market to be plugged!


And in case anyone is interested .  If you want a mechanical watch with EoT 
here's a watch selling site with a search included
http://www.chrono24.co.uk/search/index.htm?query=equation+of+time=true=1
But expect to be paying at least one kidney



Ian Maddocks
Chester, UK
53°11'50"N  2°52'41"W
frog.happy.froze




From: sundial <sundial-boun...@uni-koeln.de> on behalf of Willy Leenders 
<willy.leend...@telenet.be>
Sent: 08 October 2016 18:15
To: rodwall1...@gmail.com
Cc: Kevin Karney; Sundial list
Subject: Re: Longcase Clock with Equation of TIme


More interesting is to know whether there exist modern timepieces which 
indicate the solar time.
With the possibilities of electronics and a built-in GPS system it can not be 
so difficult.


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 8-okt-2016, om 19:32 heeft 
rodwall1...@gmail.com<mailto:rodwall1...@gmail.com> het volgende geschreven:

Hi all,

This is an interesting website on equation clocks.

https://en.m.wikipedia.org/wiki/Equation_clock

Regards,

Roderick Wall.

- Reply message -----
From: "Kevin Karney" <kar...@me.com<mailto:kar...@me.com>>
To: "rodwall1...@gmail.com<mailto:rodwall1...@gmail.com>" 
<rodwall1...@gmail.com<mailto:rodwall1...@gmail.com>>
Cc: "Sundial list" <sundial@uni-koeln.de<mailto:sundial@uni-koeln.de>>
Subject: Longcase Clock with Equation of TIme
Date: Sat, Oct 8, 2016 4:28 AM


As explained by Fred Sawyer in a recent lecture to the British Sundial Society, 
if often worked the other way around... people had an equation table and all 
kinds of rules so that they could adjust their clock so that it matched dial 
time for as long as possible.

Dial time was (and still is for some) 'true' time. The acceptance of local mean 
time was a slow process. Likewise the acceptance of national mean time met with 
a great deal of resistance. In Dorchester in 1858, in the UK, a judge in a 
court case found in favour of the plaintiff, since the defendant was not 
present at 10:00 o'clock when the case was scheduled. The court was using GMT. 
The defendant arrived at 10:00 local mean time - a few minutes late. He 
appealed and the appeal judge ruled...
"Ten o’clock is 10 o’clock according to the Time of the Place and the Town 
Council cannot say that it is not, 
but that it is 10 o’clock by Greenwich 
time. Nor can the time be altered by a railway company.… Nor by any person who 
regulates the clock on the Town-Hall."

Unless you lived in a (maritime) city, or had an astronomer on hand, or a local 
rich man who went up to the city and owned a chronometer, there was NO way to 
set a clock without a Sundial. It all changed with the the arrival of the 
telegraph....   I have found that this is something that watch and clock 
enthusiasts sometimes forget!

Kevin

Sent from my iPad

> On 7 Oct 2016, at 11:07, rodwall1...@gmail.com<mailto:rodwall1...@gmail.com> 
> <rodwall1...@gmail.com<mailto:rodwall1...@gmail.com>> wrote:
>
> Hi all,
>
> In 1730. I think I heard somewhere that. Clock manufacturers also sometimes 
> gave a small window sundial to allow you to set your clock. With a equation 
> of time table. Is that correct?
>
> Roderick Wall..
>
>
> - Reply message -
> From: "Robert Terwilliger" <

Re: Longcase Clock with Equation of TIme

[rodwall1...@gmail.com]

Hi all,
This is an interesting website on equation clocks.

https://en.m.wikipedia.org/wiki/Equation_clock

Regards,

Roderick Wall.

- Reply message -
From: "Kevin Karney" <kar...@me.com>
To: "rodwall1...@gmail.com" <rodwall1...@gmail.com>
Cc: "Sundial list" <sundial@uni-koeln.de>
Subject: Longcase Clock with Equation of TIme
Date: Sat, Oct 8, 2016 4:28 AM

As explained by Fred Sawyer in a recent lecture to the British Sundial Society, 
if often worked the other way around... people had an equation table and all 
kinds of rules so that they could adjust their clock so that it matched dial 
time for as long as possible. 

Dial time was (and still is for some) 'true' time. The acceptance of local mean 
time was a slow process. Likewise the acceptance of national mean time met with 
a great deal of resistance. In Dorchester in 1858, in the UK, a judge in a 
court case found in favour of the plaintiff, since the defendant was not 
present at 10:00 o'clock when the case was scheduled. The court was using GMT. 
The defendant arrived at 10:00 local mean time - a few minutes late. He 
appealed and the appeal judge ruled...
"Ten o’clock is 10 o’clock according to the Time of the Place and the Town 
Council cannot say that it is not, 
but that it is 10 o’clock by Greenwich 
time. Nor can the time be altered by a railway company.… Nor by any person who 
regulates the clock on the Town-Hall."

Unless you lived in a (maritime) city, or had an astronomer on hand, or a local 
rich man who went up to the city and owned a chronometer, there was NO way to 
set a clock without a Sundial. It all changed with the the arrival of the 
telegraph   I have found that this is something that watch and clock 
enthusiasts sometimes forget!

Kevin

Sent from my iPad

> On 7 Oct 2016, at 11:07, rodwall1...@gmail.com <rodwall1...@gmail.com> wrote:
> 
> Hi all,
> 
> In 1730. I think I heard somewhere that. Clock manufacturers also sometimes 
> gave a small window sundial to allow you to set your clock. With a equation 
> of time table. Is that correct?
> 
> Roderick Wall..
> 
> 
> - Reply message -
> From: "Robert Terwilliger" <b...@twigsdigs.com>
> To: "'Ian Maddocks'" <ian_maddo...@hotmail.com>, "'Sundial list'" 
> <sundial@uni-koeln.de>
> Subject: Longcase Clock with Equation of TIme
> Date: Fri, Oct 7, 2016 1:00 PM
> 
> If you had a similar clock in 1730 - located where you didn't have access to
> another accurate clock, a sundial would be the only way you could set it -
> and to do so you would need to know the equation for the date. 
> 
>  
> 
> Bob
> 
>  
> 
>   _  
> 
> From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Ian
> Maddocks
> Sent: Wednesday, October 5, 2016 12:29 PM
> To: Sundial list
> Subject: Longcase Clock with Equation of TIme
> 
>  
> 
> hi folks
> 
>  
> 
> I was just blundering around the internet when I came across the following
> that may be of interest..
> 
>  
> 
> A long case clock from 1730 London that has an annual dial for displaying
> the date and the equation of time
> 
> http://www.raffetyclocks.com/antique-clocks/d/antique-month-equation-and-yea
> r-calendar-longcase-clock-by-john-topping-london/170271
> 
> It's a premade disk with EoT table that rotates in a year, not a P type
> kidney cam, but was new clock complication to me
> 
>  
> 
> greetings from 
> 
>  
> 
> Ian Maddocks
> Chester, UK
> 53°11'50"N  2°52'41"W
> frog.happy.froze
> 
>  
> 
>  
> 
>  
> 
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Longcase Clock with Equation of TIme

[rodwall1...@gmail.com]

Hi all,
And thanks to all who commented on clocks that have the equation of time on the 
dial. So many of you had something interesting from court cases, bath clocks, 
watches with equation dials etc. 

I did not know that there were clocks that had equation of time dials. I always 
thought that a equation of time table was use to set the clocks from sundials.

I would love to have a watch or pocket watch or even a clock that has a 
equation of time dial. But not at the $30,000 prices that they are asking.
Is there any reasonably priced modern clocks or watches today that have the 
equation of time dials?

Thanks all for such a interesting subject. So many of you have so much 
interesting knowledge thanks.

Regards,

Roderick Wall.

- Reply message -
From: "Kevin Karney" <kar...@me.com>
To: "rodwall1...@gmail.com" <rodwall1...@gmail.com>
Cc: "Sundial list" <sundial@uni-koeln.de>
Subject: Longcase Clock with Equation of TIme
Date: Sat, Oct 8, 2016 4:28 AM

As explained by Fred Sawyer in a recent lecture to the British Sundial Society, 
if often worked the other way around... people had an equation table and all 
kinds of rules so that they could adjust their clock so that it matched dial 
time for as long as possible. 

Dial time was (and still is for some) 'true' time. The acceptance of local mean 
time was a slow process. Likewise the acceptance of national mean time met with 
a great deal of resistance. In Dorchester in 1858, in the UK, a judge in a 
court case found in favour of the plaintiff, since the defendant was not 
present at 10:00 o'clock when the case was scheduled. The court was using GMT. 
The defendant arrived at 10:00 local mean time - a few minutes late. He 
appealed and the appeal judge ruled...
"Ten o’clock is 10 o’clock according to the Time of the Place and the Town 
Council cannot say that it is not, 
but that it is 10 o’clock by Greenwich 
time. Nor can the time be altered by a railway company.… Nor by any person who 
regulates the clock on the Town-Hall."

Unless you lived in a (maritime) city, or had an astronomer on hand, or a local 
rich man who went up to the city and owned a chronometer, there was NO way to 
set a clock without a Sundial. It all changed with the the arrival of the 
telegraph   I have found that this is something that watch and clock 
enthusiasts sometimes forget!

Kevin

Sent from my iPad

> On 7 Oct 2016, at 11:07, rodwall1...@gmail.com <rodwall1...@gmail.com> wrote:
> 
> Hi all,
> 
> In 1730. I think I heard somewhere that. Clock manufacturers also sometimes 
> gave a small window sundial to allow you to set your clock. With a equation 
> of time table. Is that correct?
> 
> Roderick Wall..
> 
> 
> - Reply message -
> From: "Robert Terwilliger" <b...@twigsdigs.com>
> To: "'Ian Maddocks'" <ian_maddo...@hotmail.com>, "'Sundial list'" 
> <sundial@uni-koeln.de>
> Subject: Longcase Clock with Equation of TIme
> Date: Fri, Oct 7, 2016 1:00 PM
> 
> If you had a similar clock in 1730 - located where you didn't have access to
> another accurate clock, a sundial would be the only way you could set it -
> and to do so you would need to know the equation for the date. 
> 
>  
> 
> Bob
> 
>  
> 
>   _  
> 
> From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Ian
> Maddocks
> Sent: Wednesday, October 5, 2016 12:29 PM
> To: Sundial list
> Subject: Longcase Clock with Equation of TIme
> 
>  
> 
> hi folks
> 
>  
> 
> I was just blundering around the internet when I came across the following
> that may be of interest..
> 
>  
> 
> A long case clock from 1730 London that has an annual dial for displaying
> the date and the equation of time
> 
> http://www.raffetyclocks.com/antique-clocks/d/antique-month-equation-and-yea
> r-calendar-longcase-clock-by-john-topping-london/170271
> 
> It's a premade disk with EoT table that rotates in a year, not a P type
> kidney cam, but was new clock complication to me
> 
>  
> 
> greetings from 
> 
>  
> 
> Ian Maddocks
> Chester, UK
> 53°11'50"N  2°52'41"W
> frog.happy.froze
> 
>  
> 
>  
> 
>  
> 
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Longcase Clock with Equation of TIme

[rodwall1...@gmail.com]

Hi all,
In 1730. I think I heard somewhere that. Clock manufacturers also sometimes 
gave a small window sundial to allow you to set your clock. With a equation of 
time table. Is that correct?

Roderick Wall..

- Reply message -
From: "Robert Terwilliger" 
To: "'Ian Maddocks'" , "'Sundial list'" 

Subject: Longcase Clock with Equation of TIme
Date: Fri, Oct 7, 2016 1:00 PM

If you had a similar clock in 1730 - located where you didn't have access to
another accurate clock, a sundial would be the only way you could set it -
and to do so you would need to know the equation for the date. 



Bob



_  

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Ian
Maddocks
Sent: Wednesday, October 5, 2016 12:29 PM
To: Sundial list
Subject: Longcase Clock with Equation of TIme



hi folks



I was just blundering around the internet when I came across the following
that may be of interest..



A long case clock from 1730 London that has an annual dial for displaying
the date and the equation of time

http://www.raffetyclocks.com/antique-clocks/d/antique-month-equation-and-yea
r-calendar-longcase-clock-by-john-topping-london/170271

It's a premade disk with EoT table that rotates in a year, not a P type
kidney cam, but was new clock complication to me



greetings from 



Ian Maddocks
Chester, UK
53°11'50"N  2°52'41"W
frog.happy.froze---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Longcase Clock with Equation of TIme

[rodwall1...@gmail.com]

Hi Ian,
Thanks for this link. Very interesting I've never see this before.

I wonder if there are any other clocks with the equation of time on the dial.

And in what form is the equation of time shown on the clock dial.

Regards,

Roderick Wall.

- Reply message -
From: "Ian Maddocks" 
To: "Sundial list" 
Subject: Longcase Clock with Equation of TIme
Date: Thu, Oct 6, 2016 3:28 AM

hi folks


I was just blundering around the internet when I came across the following that 
may be of interest..


A long case clock from 1730 London that has an annual dial for displaying the 
date and the equation of time

http://www.raffetyclocks.com/antique-clocks/d/antique-month-equation-and-year-calendar-longcase-clock-by-john-topping-london/170271
It's a premade disk with EoT table that rotates in a year, not a P type 
kidney cam, but was new clock complication to me

greetings from

Ian Maddocks
Chester, UK
53°11'50"N  2°52'41"W
frog.happy.froze---
https://lists.uni-koeln.de/mailman/listinfo/sundial