Sun dials and astronomical clocks

1
Astronomical Clocks

My travels this Summer took me to Switzerland, which gave me the opportunity to study the 15th century astronomical clock of Berne. The chronological detail and accuracy displayed by this time-piece is truly facinating and wikipedia have a good article on the history and origin of both the Tower and Clock. http://en.wikipedia.org/wiki/Zytglogge
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From the site http://en.wikipedia.org/wiki/Zytglogge you may reach an image with even finer resolution. Among the many fascinating details the observer may note how the clock includes a system for measuring the local sunrise and sunset, which varies according to the months and season of the year, and the Moon is presented as a little globe that twirls during the lunar month, as to correctly and visually display the lunar phases. This means that the clock takes into account both the synodic and sideral lunar month.

I was listening to a guide tell tourists how the clock showed the astrological signs. I almost felt like interrupting and adding: "It doesn't actually show the astrological signs, as this is not due to have been its primary function, but it does show the tropical zodiac as an astronomical measure of the seasons and the time of the year. This also happens to be the basis of the 12 signs used in astrology, which does show the close relationship between classical astronomy and astrology."
Last edited by Andrew Bevan on Tue Aug 26, 2008 10:06 am, edited 1 time in total.
http://www.astronor.com

2
Sundials
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Another interesting attraction was the Sundial on the wall of Hotel Murtenhof. A staff casts its shaddow on a wall. The shaddow does not only show local time, but the length of shaddow is also defined within the tropical zodiac, which shows the observer the month or rather time or season of the year. The Sun dial is interesting from an astrological perspective because it so easily decribes the equal signs, or signs that see each other; those months when the Sun is equally distant from the equator and the intervals of day and night are of equal length. This is applied in astrology as it is the basis of the antiscia.
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Hotel Murtenhof & Krone - www.murtenhof.ch
http://www.astronor.com

4
Astronomical Clocks

The Upper Dial of the Tower Clock in Berne is much more simple in design. Here the hand, or rather arrow, of the Sun and the Moon, indicates the hour of the Day. The hour was all important in the 15th Century. The hand showing the minutes of the hour is a modern addition to the Clock.
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I highly recommend visiting Wikipedia for their description of the historical and technical details: http://en.wikipedia.org/wiki/Zytglogge
From Wikipedia:
The painted frieze above the astronomical clock shows five deities from classical antiquity, each representing both a day of the week and a planet in their order according to Ptolemaic cosmology. From left to right, they are: Saturn with sickle and club for Saturday, Jupiter with thunderbolts for Thursday, Mars with sword and shield for Tuesday, Venus with Cupid for Friday and Mercury with staff and bag for Wednesday.
Don't forget to visit the website dedicated to this Clock at http://www.zeitglockenturm.ch/index.php ... =1&clang=1
http://www.astronor.com