Gears are the glorious invention that makes things move and do wonderful things. Old clocks move without any electricity and are perhaps the most practical and representative example of a machine consisting of gears.

Since its invention by Zhang Heng, one of the greatest Chinese mathematicians, the clock has become an indispensable part of people’s lives. With modern technological advances, however, old clocks running on gears have largely been replaced by clocks and watches that run on electricity. However, old clocks retain that special magical power in that they crystallize the collective wisdom of human ingenuity. Turning gears of old clocks never fail to enchant the admirer, and this is perhaps why clocks and watches made by master watchmakers and clockmakers not only retain but also rise in their value. They are family heirlooms and investment.

This book shows the magnificent inner workings and gears of old clocks by illustrating their various parts and mechanisms through their rebuilding and restoration process.