October 1856: The Westminster Clock

And in 1856, shortly before its installation in the Westminster’s iconic tower The Engineer took a look at a device that’s still considered by many to be one of the finest and most innovative mechanical clocks ever to be built.

Designed in the 1840’s by lawyer and amateur horologist Sir Edward Beckett Denison, the Great Westminster clock represented a fundamental breakthrough in clock design.

“The merit of the design of the Westminster clock is due to Edmund Beckett Denison,” reported The Engineer, “a gentleman who has devoted very considerable time to the study of clock and watch-making and who has at various times introduced many important improvements in their construction.”

At its heart is an innovation that’s been hailed as one of the most significant horological advances of the 19th century: the double three-legged gravity escapement.

An escapement is the device in a mechanical clock that transfers energy to its time keeping element. It’s driven by force from a coiled spring or weight that’s transmitted through the clock’s gear train. Each swing of the pendulum releases a tooth of the escapement’s gear wheel – allowing the gear train to advance by a fixed amount.