Strictly speaking, "Big Ben" is the name given to the bell which hangs in the tower, the chimes of which are regularly broadcast by the B.B.C. Popularly, the name is often used to include the clock itself, of which the bell is a part.
The bell was originally hung in 1856, but it was not till 1859 that the clock was actually started. Big Ben weighs 13 1/2 tons, and the Clock Tower is 320 feet high. The minute hand of the clock is 14 feet long, while the hour hand measures 11 feet. The clock has been described as the "grandfather of all clocks", and it is still, as when first erected, one of the most accurate as well as one of the largest in the world.
The name of Big Ben was taken from Sir Benjamin Hall, a big genial man who was First Commissioner of Works during the years when the great clock and bell were installed. The clock was successfully started on May 31st 1859, after the weight of the bell had been reduced from 15 to 13 1/2 tons. The clapper was also reduced to 4 cwt. It is without doubt the best-known clock in the world and there are few countries in which the chimes and strike of Big Ben have not been heard by radio.