May 1905: Obituary of Edmund Beckett Denison, Baron Grimthorpe

As the General Election looms and the thoughts of the nation turn, however reluctantly, to Westminster, we can be certain that we’re going to see the most distinctive feature of the Houses of Parliament, the clock that we’re not supposed to call Big Ben, ever more regularly on our TV screens and newspapers. The engineer who designed that clock, and the mechanism that produces its evocative chimes, was Edmund Beckett Denison, later raised to the House of Lords as the first Lord Grimthorpe, whose brief obituary appeared in The Engineer.

For our predecessors, Grimthorpe was notable for his clock making: he revolutionised the building of large public clocks. He invented a system that more or less eliminated friction in the clock’s escapement — the component of the mechanism that converts the oscillation of the pendulum into the rotation of the escape wheel, the largest of the clock movement’s gears. Previously, large pendulum clocks, such as those in churches, used a system called a remontoire escapement, which used a secondary source of power — a small weight or spring — to drive the clock’s escape wheel. Every half-minute, the clock’s pendulum mechanism winds up this secondary power source, so the clock’s arms — which would be very large, heavy and liable to be caught by the wind — are isolated from the movement of the pendulum and vice-versa.