Commentary: Connections - Tick Tock; August 1998; Scientific American Magazine; by Burke; 2 Page(s)

Walking through Parliament Square in London the other day, I suddenly remembered that when I was a very small child during World War II, the sound of Big Ben ringing the hour on the radio was a comforting indication that it hadn¿t been hit by incoming German V-1 missiles.

In 1859 the new Big Ben clock became the miracle of harrumph high-tech precision (as had been promised by Prime Minister George Canning) when the gravity escapement system created by E. Beckett Denison was installed. Denison¿s trick for isolating the movement of the pendulum from that of the gears worked in such a way that no matter how much dirt or ice accumulated on the four sets of clock hands, Big Ben would keep time accurate to the second. (Thank you, Frederickton, New Brunswick, on whose often icy cathedral clock Denison had done a wet run.)