Fer;
On the dial you reference below:
http://www.de-zonnewijzerkring.nl
the azimuth scale reads from left to right: 80-90-100-90-80
But on the wall dial here:
http://www.sundialsatlas.eu/atlas.php?PHPSESSID=8e74105bf2da4262cba08780f5d6a131
left to right reads:
80-90-100-10-20
Can you explain why?
thanks;
brent
fer de vries wrote:
Frank,
For another French Revolution sundial look at the website of "De
Zonnewijzerkring".
Address below.
Look for:
article of the month
archives 2005
month 05-04, (April)
You see at noon it is 5 decimal time.
Around the dial is a double scale for azimuth in 400 degrees with 0 and
100 at noon.
And a second azimuth scale with names of the direction as in the usual
system.
Best wishes,
Fer J. de Vries
De Zonnewijzerkring
http://www.de-zonnewijzerkring.nl
Molens
http://www.collsemolen.dse.nl
Eindhoven, Netherlands
lat. 51:30 N long. 5:30 E
----- Original Message ----- From: "Frank King" <frank.k...@cl.cam.ac.uk>
To: <bren...@verizon.net>
Cc: "Sundial List" <sund...@rrz.uni-koeln.de>
Sent: Wednesday, January 19, 2011 5:44 PM
Subject: Re: 360 degree/Fabian
Dear Brent,
You correctly note...
It looks like the date must have changed at noon.
Indeed so. Interestingly, even with GMT (as used by
astronomers and navigators) the date used to change
at noon (which was referred to as 0h GMT). This was
the case until 1 January 1925, so not very long ago!
See:
http://en.wikipedia.org/wiki/Greenwich_Mean_Time
Historians can be confused by this. They will read
an entry in a ship's log recording landfall at a
certain time on a certain date and fail to interpret
the information correctly.
While it is well established that the date changed
at noon I haven't actually seen it written down that
the day changed at noon too. Can anyone confirm this
and give a reference?
A good many people don't know the day's date without
checking but most know the day of the week. It would
be odd to have the date changing at one time and the
day at another.
I didn't know that French Revolutionary Time had the
date changing at noon but that would fit with the
way I think French Navigation Tables were published
at the time. Can anyone confirm that?
Napoleon had a go at almost anything that used
base 12 or a multiple of 12 but, looking at the
sundial at
www.sundialatlas.eu/atlas.php?so=IT2810
it seems that Napoleon forgot to change the number
of Signs of the Zodiac to 10.
I wonder how he would have done that :-)
You can't simply drop the two Signs you least like
and spread the others out!!
All the best
Frank H. King
Cambridge, UK
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