Thursday, November 08, 2012

Build an Edo-style clock that measures unequal hours

Image of an Edo-style clock

I was reading a history book this week called The Discoverers by Daniel J. Boorstin. The first of the three sections of the book deals with the subject of time. The invention of the mechanical clock is a surprisingly recent one. This means that the hour as we know it is also a fairly recent concept. The minute is still more recent. This fact is evident from some of the earliest mechanical clocks in Europe which have no minute hand at all. To this point, this material was familiar to me. It's only when the author turned his attention to the Japanese approach to the hour that my head was sent spinning.

The clocks developed in the Western world divided the day into 24 hours of equal length. This may seem logical to us now, but only because we have lived with it our entire lives. Before the clock was commonplace, a person's day was regulated by the light provided by the sun. In such a world, if you lived anywhere but on the equator, the length of your sunlit day changed with the seasons. If the length of the day changed, why not have the units that divide the day change in length also? This is apparently what the Japanese did.

During the Edo period, the Japanese employed a system of unequal hours based on sunrise and sunset. As the seasons changed, the length of a single hour also changed. It's an interesting concept to try to get your head around, is it not? What is even more fascinating to me is that the Japanese developed a mechanical clock that used this system. As if building a machine to keep regular time wasn't difficult enough, imagine designing one in which the length of an hour changed from day to day. But the complexities don't end there. If the season one was in had short days and long nights, that means hours during the day were shorter than hours at night. Not only do hours change from day to day, but also from day to night!

Imagine my delight, then, when I yesterday I also received a newsletters from the Maker Shed. They are having an overstock sale on various items -- one of which is the Edo-Style Clock Kit shown in the picture above.

Image showing kit being assembled

I, for one, can't wait to learn how this amazing clock works. I've worked on a few real antique clocks, so much of what I will find in the kit should be familiar to me. If you haven't worked on clocks before, I imagine this kit would be a great introduction to learning how clocks work. Like many of the Gakken kits, the instructions are well-illustrated, but written in Japanese. Problem? Nope. You need only to visit the in-depth assembly guide titled Build a Gakken Edo-Style Clock created by Marc de Vinck that is posted on the Make Projects web site. The picture above comes from that project guide.

Though the Gakken Double-foliot Japanese Clock Kit is available from Amazon, the price is far better in the Maker Shed.

Labels: , , , , , , , , , , ,


Post a Comment

<< Home