This is the top of the pendulum. It also extends down to the floor below.
A set of weights provide the power to the clock. The gears here form the heart of the timekeeping portion of the clock. The small 9-inch clock is used to set the larger clock because you cannot see the hands from the inside.

The clock is still wound manually, though a small electric motor is used to make the task a little less arduous.

At the top of the clock is the crown gear. This gear, in turn, drives the four gears connected to each of the four faces of the clock.
  More views of the clock...