In the technology center of the Festo Company in Esslingen, Germany, you can see the amazing FESTO Harmonices Mundi.

From their web site:

Festo’s Technology Centre features an attraction of a symbolic nature, namely the Harmonices Mundi. This technical work of art consists of three parts – a world time clock, an astronomical clock and a glockenspiel – embodying the company’s innovative power and precision work.The Harmonices Mundi combines astronomy, mechanics, melodics and electronics. The name is based on a book of the same name written by Johannes Kepler in 1619. In this book, Kepler defines the laws that describe the structure of our planetary system. Fascinated by historical astronomy, Prof. Hans Scheurenbrand (a former member of the Managing Board) spent years working in his leisure time constructing the Harmonices Mundi for Festo.The three-part Harmonices Mundi also includes a modern glockenspiel, with 76 bells and 40 claves that can be struck to obtain various levels of sound.

With this clock the Professor is merging two cultures. The medieval desire to construct an analog simulation of the universe in clockwork, seen in many of the classic old astronomical clocks of the last 500 years, meets the modern obsession with visibility, documentation, and machine-like precision of design and manufacture. Every aspect of the clock’s construction has been meticulously described and illustrated (you can buy the book). You can also browse through this PDF (also in German), for more illustrations and a feel for the mathematical precision that’s going on behind the scenes.

The superb visual design of the project can be further explored on the web site of Linden-based agency Hild Design who worked on the graphics and typography. And you’ll also find an extract from Novum magazine on their site with some more luscious graphics.

It’s not obvious to me whether you can visit this clock if you’re passing through Esslingen, Germany. Perhaps someone can find out?

Thanks to Tommy for passing this on.

This weekend, the restored clock in St Mark’s Venice was unveiled.

The clock was first installed 500 years ago, and has seen many changes and restorations in its time. In the 1850s an illuminated digital display was added for telling the time at night.

You can read more about this clock, and the controversial restoration, in English (grazie!) at Orologeria.

Thanks to David Evans for this picture. He writes:

I discovered this clock in Cpo SS Apostoli in Venice (between Ca D’Oro and Rialto Bridge. Can anyone explain how you use it?

The vagaries of medieval and renaissance Italian time-keeping are mentioned elsewhere on the site. My understanding is that the Italians started their counting from 1 at twilight or sunset, and counted all the way through the night, reaching 24 just before sunset (if things went like clockwork).

I don’t know whether ‘the authorities’ run any of their surviving clocks on the original schedules, maintaining the authentic ‘Italian hours’, for the benefit of tourists and the inconvenience of the residents. The central pointer is similar to the other Venice clock, although perhaps less easy to read. To my eyes, this clock says about 6. It’s obviously not midnight or 6 hours after sunset, so I think we can dismiss the ‘Italian hours’ idea. If the picture was taken at 6 or 7 in the morning (allowing for Daylight Saving Time), then the clock might either be working really well, or it’s broken, the photographer was lucky enough to be there at the one time of day when the clock was reading the right time.

More likely, though, the clock is either not working or not keeping the right time. You’ll have to go back and do some more research, David!

Tommy Toverud writes from Norway to tell me about this French site that describes a number of astronomical clocks in Europe.

http://www.ens-lyon.fr/RELIE/Cadrans/

Here’s a wonderful clock from Stendal in Germany.