6
Escape Wheel
Weight
Escapement
Winding
Cord
Pendulum
Shaft
How the Tranquility Clock Works
It will be helpful to have an understanding of how the Tranquility clock works.
This knowledge will be beneficial in assembling the clock.
The Tranquility clock is driven by weight. The weight is hung from a cord that is
wound around a spool on the great wheel arbor (shaft). The weight unwinds the cord from
the spool, causing the arbor to rotate. The gears that are attached to this arbor mesh with a
train of other gears, causing them to rotate as well. When the cord has unwound to a point
where the weight has nearly reached the floor, the clock is “wound” by winding the cord
back around the arbor.
The speed at which the weight is allowed to rotate the gear train is regulated by the
pendulum. As the pendulum swings back and forth, it causes the escape lever to rock back
and forth along with the pendulum. The escape lever alternately stops and then releases
one of the gears in the train (called the escape wheel).
The faster the pendulum moves back and forth, the faster the escape wheel (and the
entire gear train) will be allowed to advance. The pendulum swing period is determined
by its length (or, more precisely, the length from its pivot point to its center of gravity).
Increasing the pendulum length increases the time it takes the pendulum to complete its
swing. This makes the clock run slower. Decreasing the pendulum length decreases the
time it takes the pendulum to complete its swing, making the clock run faster. Therefore,
adjusting the position of the pendulum bob along the pendulum shaft controls whether the
clock runs fast or slow and provides a means by which the clock can be made to run “on
time.”