This is my fifth wooden clock; the first one was made in 1971. Each time, I have tried to make the mechanism a little bit simpler. This one has a long slow pendulum swinging once every 1.5 seconds, instead of the more usual one second, thus reducing the number of pins on the smaller wheel. You may like to figure out how the 12: 1 reduction ratio between the minute hand and hour hand works. Hint: the small wheel with 11 teeth does not move at all. This mechanism was invented by Aaron Dodd Crane in the 19th century. The escapement is based on John Harrison's low friction Grasshopper escapement from the early 18th century. The position of the pendulum weight is currently being adjusted to compensate for the lower latitude (Tokyo: 34⁰ 41' N, Berlin: 52⁰.31') and the higher humidity. (These occasional adjustments to improve the timekeeping are recorded on the handwritten note).

M. R.