John Harrison
John Harrison is famous because he was the first person to make a clock that could tell the time accurately on board a ship. He was born in 1693 in Yorkshire and died in 1776 when he was 82 years old. To begin with he worked in his father's workshop as a carpenter but he also did some jobs that were more mathematical like surveying and measuring land. Only later on did he start making clocks. The first clock he made was made out of wood.

Making a clock that could tell the time accurately at sea was very difficult because the ship would be tossed around by the waves. However, it was very important to be able to tell the time accurately at sea because before satellite navigation the only way that ships could work out their positions accurately was by using a clock. Because Britain had a very large navy, in 1713 the Houses of Parliament offered a prize of 20,000 pounds to anyone who could make a clock that told the time accurately at sea. Starting in 1728 John Harrison made four different clocks for telling the time at sea which he called 'Marine Chronometers'. He entered them in the prize competition in 1735. After parliament tested his clocks and found them to work at sea many people thought that Harrison should have won the prize. However, it wasn't until 1773 that Harrison was given all the prize money, only three years before he died. Because of this many people think that Harrison was a mechanical genius who was very badly treated by the scientists and politicians.