51�Թ�

The piece driven by the pendulum is a rare Denison double three-legged gravity escapement, he added - originally developed for Big Ben in London, he said it’s the most accurate type of escapement for a tower clock mechanism.

It was a relic of the past, an original E. Howard clock from Boston, Model No. 3 gravity escapement.

A better construction, afterwards introduced, is to make the fly separate from the letting-off arms, whereby the blow on the cylinder is diminished, the fly being allowed to go on as in the gravity escapement.

No turret clock without either a train remontoire or a gravity escapement will approach that degree of accuracy.

The double three-legged gravity escapement, which was first used in the Westminster clock, is shown in fig.