Precision Regulator, No. 193 for Princeton College Observatory

An exceptional high precision floorstanding regulator signed E. Howard & Co., Boston, No. 193. The substantial movement has screw-fixed pillars, single four-legged gravity escapement, mercury pendulum with precision rating nut. Each gravity or impulse arm is lifted and falls alternatively.

The gravity escapement was initially invented for use in the clock in Westminster, ‘Big Ben’. It had many precision advantages, including superior accuracy in weather conditions, and the changing condition of the oil due to weather would not affect its rate.

Major observatories had a ‘clock vault’ where environmental conditions were carefully controlled and several regulators were compared for accuracy. This No. 193 regulator, together with the No. 194, was used as the timekeeper for the Princeton College Observatory (later Princeton University) for fifty years from 1877.