Watson Clock Drive

As a professional instrument in its day, the Watson telescope's mechanical accuracy rivals the best telescopes currently being
made. It employed a mechanism to track astronomical targets in right ascension that was driven by a small motor regulated by
a series of falling weights and a swinging pendulum, much like a grandfather clock. When originally decommissioned in 1988,
the tracking was found to lose only 1 second per month of continual tracking.

It was this kind of original clock-regulated tracking mechanism that gave rise to the name of right ascension motors still used on
telescopes to this day. Although now regulated with electronic circuitry, they are still called " clock drives". This part of the
original telescope will not be reused. HAL plans to retrofit the Watson scope with a modern computer controlled tracking
mechanism.

Clock Drive Photos