Palace of Westminster
Exterior
Five bells hang in the belfry above the clock. The four quarter bells strike the Westminster Chimes every quarter-hour. The largest bell strikes the hours; officially called The Great Bell of Westminster, it is generally referred to as Big Ben, a nickname of uncertain origins which, over time, has been colloquially applied to the whole tower. The first bell to bear this name cracked during testing and was recast; the present bell later developed a crack of its own, which gives it a distinctive sound. It is the third-heaviest bell in Britain, weighing 13.8 tonnes. In the lantern at the top of Elizabeth Tower is the Ayrton Light, which is lit when either House of Parliament is sitting after dark. It was installed in 1885 at the request of Queen Victoria—so that she could see from Buckingham Palace whether the members were "at work"—and named after Acton Smee Ayrton, who was First Commissioner of Works in the 1870s.
Palace of Westminster-30