Here is a reference from Wikipedia on Republican time. The "Les Vigneaux"
sundial follows the decree of 1793 that defined republican time.
http://en.wikipedia.org/wiki/Decimal_time
"In more modern times, decimal time was introduced during the French
Revolution in the decree of 5 October 1793:
XI. Le jour, de minuit à minuit, est divisé en dix parties, chaque partie en
dix autres, ainsi de suite jusqu'à la plus petite portion commensurable de
la durée.
XI. The day, from midnight to midnight, is divided into ten parts, each part
into ten others, so on until the smallest measurable portion of duration.
These parts were named on 24 November 1793 (4 Frimaire of the Year II). The
primary divisions were called hours, and they added:
La centième partie de l'heure est appelée minute décimale; la centième
partie de la minute est appelée seconde décimale. (emphasis in original)
The hundredth part of the hour is called decimal minute; the hundredth part
of the minute is called decimal second.
Thus, midnight was reckoned as 10 o'clock, noon as 5 o'clock, etc. Although
clocks and watches were produced with faces showing both standard time with
numbers 1-24 and decimal time with numbers 1-10, decimal time never caught
on; it was not officially used until the beginning of the Republican year
III, 22 September 1794, and mandatory use was suspended 7 April 1795 (18
Germinal of the Year III), in the same law which introduced the original
metric system. Thus, the metric system at first had no time unit, and later
versions of the metric system used the second, equal to 1/86400 day, as the
metric time unit."
Roger
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From: "Roger Bailey" <rtbai...@telus.net>
Sent: Thursday, January 20, 2011 10:14 AM
To: "Roger Bailey" <rtbai...@telus.net>; <bren...@verizon.net>; "Sundial
List" <sund...@rrz.uni-koeln.de>
Subject: Re: 360 degree
The confusion on noon has nothing to do with the day starting at midnight
or noon. It has to do with the definition of the Republican hour. Were
there 10 hours per day as shown on the "Les Vigneaux" sundial or two 10
hour periods starting at midnight and noon? I guess it is two 10 hour
periods, like our two 12 hour periods. This would allow clock makers to
just change the face of the 12 hour clock to a 10 hour clock. Otherwise
the gears would have to be changed to give a 24 hour, 10 Republican hour
clock.
The "Les Vigneaux" sundial is unusual as it is north facing, declining
east, showing early morning hours. The sun would not be on the dial at
noon. If an hour line for noon were drawn on the dial, it would be, as
always on a VD sundial, a vertical line, the meridian, marked as 5 hours.
I was drawn to this location by the corner dials on the village church.
The Republican sundial was right next door.
See:
http://www.waymarking.com/waymarks/WM7EV1_Corner_Sundials_on_Church_Tower_Les_Vigneaux_Vallouise_Hautes_Alpes_France
Regards,
Roger Bailey
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From: "Roger Bailey" <rtbai...@telus.net>
Sent: Tuesday, January 18, 2011 8:16 PM
To: <bren...@verizon.net>; "Sundial List" <sund...@rrz.uni-koeln.de>
Subject: Re: 360 degree
Hi Brent,
If you were in charge of things, we could call you Napoleon. What you are
proposing is the French Republican system, the metric system applied to
time, 100 grad for a quadrant, 90 degrees, 10 hours a day, 100 minutes
per hour, all totally rational. They even produced clocks and sundials
based on these rational, ok decimal, systems. A few still exist. Here is
my favourite example, a Republican sundial with a relativistic
correction. See
http://www.waymarking.com/waymarks/WM7ETZ_Republican_Sundial_Les_Vigneaux_Vallouise_Hautes_Alpes_France
As this is a text message, paste the url into your browser to see this
fine sundial.
Regards, Roger Bailey
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