Aitkenhead Clock

The hour hand keeps time from the clock's center while the minute hand orbits around. At first glance it is puzzling how this timepiece works, because the minute hand does not appear to be attached to the axis. In actuality, the minute hand is fixed to the disk that makes up the clock face. The entire disk rotates, but seems motionless, because it is perfectly round, and featureless. The hour hand is attached to a pin that protrudes from a hole in the center.