Article of the month April

Decimal hours

We have become accustomed to the day being been divided into 24 hours of 60 minutes each, and that a minute being divided into 60 seconds.
During the French revolution, a time system was introduced that divided a day into 10 hours of 100 minutes each, and a minute into 100 seconds, in accordance with the decimal system.
That is quite possible, but the system has only been in use for some years.

Some sundials still exist that use this time system.
A beautiful example is this porcelain horizontal sundial.

On the sundial, we see the decimal divisions - from 2 hours up to and including 8 hours, with subdivisions to 10 minutes and 1 minute - as well as the usual solar time hours, from slightly before VI (6) hours up to well after VI (18) hours in quarter hours.
Supposedly, by having both time systems on the dial, one could get used to the new hours.

The sundial furthermore shows an equation-of-time loop and an azimuth scale in 400 decimal degrees.