On Astronomy’s August tour of London, some 25 readers and I had the great pleasure of seeing many important astronomical sites in England. One of those majestic places was the Royal Observatory Greenwich, and I shot some videos during parts of the trip.
You may not know about one of the Royal Observatory’s most famous early astronomers, John Harrison (1693–1776). In Harrison’s day, one of the primary areas in which astronomy helped the world was in navigation on the high seas. But there was a major problem — clocks were not reliable enough to deliver precise time over long periods, far away from the Greenwich Mean Time of the Royal Observatory itself. The determination of longitude while at sea was unreliable as well. Harrison invented several successive clocks, the most famous of which was his marine chronometer (Harrison’s “fourth timekeeper”). This instrument solved the longitude problem and made navigation at sea practical. It was one of the keys to enabling the British Empire to explode in influence.
While at the Observatory I shot several short videos of Harrison’s timekeepers, posted below..
They show Harrison’s first timekeeper, second timekeeper, third timekeeper, and the hugely important fourth timekeeper. I also have a short video of a portrait of Harrison and other artifacts, and a video of the modern equivalent of Harrison’s devices, an atomic clock.
Enjoy the videos, and I will post more of these soon.