by a working class man from Lincolnshire. His name was John Harrison. John Harrison took little formal education. However, he took on the scientific and academic establishment of his time and won the longitude prize. He had extraordinary mechanical insight, talent and determination, developed in his career as a clockmaker. Harrison was born in Foulby in Yorkshire in 1693. His father was a carpenter and John followed the family bussiness. During the latter part of his early career, he worked with his younger brother James. During the 1720s, John and James designed a series of remarkable precision longcase clocks. Their career made them become the best clockmaker in London.
Then, they decided to make a new extraordinary clock that can measure the longitude on the sea. To solve the longitude problem, Harrison would have to devise a portable clock which kept time to the same accuracy.
H1 (1730-1735)
It was constructed between 1730 and 1735. H1 is a portable version of Harrison's wooden clocks. He was full of confidence to make a precise clock that ticked away the minutes. The moving parts are controlled by springs so that, H1 is independent of the direction of gravity. H1 was brought to London in 1735 and displayed to the scientific community. In 1736, Harrison and his timekeeper departured to Lisbon to test the clock. H1 performed well in the trial, however, Harrison was not satisfied.
H2 & H3 (1737-1759)
arger and heavier than H1. Harrison began his work on H2 in 1737. Soon he realised its design was wrong. The bar balances did not work well. Harrison requested more money from the Board to work on a 3th timekeeper.
These two inventions are used in a variety of machines nowadays. H3 seemed to solve the problem, but the problem wasn't so easy.
These invention were too heavy to carry any where on the ships. John decied to invent an entirely different type.
H4 (1755-1759)
In 1753, Harrison commissioned London watchmaker John Jefferys to make him a watch following Harrison's own designs. H4 is completely different from the other three types of timekeeper. Just 13 cm in diameter and weighing 1.45 kg.
Through two time trials, his clock proved itself as the right timekeeper for the long voyage. Harrison disclosed his secret clock and its mechanisms to the Astronomer Royal. Soon he started to make the next version, H5. H5 was put on trial by the King himself in 1772, and performed perfectly.
In the meantime, Captain Cook had set out on his second voyage of discovery with K1, Kendall's copy of H4.
Famous explor in Britain, Captain Cook
He returned in July 1775. His long voyage took three years to finish which was from the Tropics to the Antarctic. It is said that the daily rate of K1 never exceeded 8 seconds. During the entire voyage, Cook referred to the watch as
...our faithful guide through all the vicissitudes of climates.
Cook's successful voyage proved that longitude could be measured from a watch. John Harrison died almost one year after Cook's return, on 24 March 1776, in his house in London.
He was 83 years old.