John Harrison

John Harrison

English carpenter and self-taught watchmaker
Date of Birth: 24.03.1693
Country: Great Britain

  1. Biography of John Harrison
  2. Early Life and Career
  3. The Marine Chronometer

Biography of John Harrison

John Harrison was an English carpenter and self-taught clockmaker who gained fame as the inventor of the marine chronometer, a device that solved the problem of determining longitude at sea. This problem was considered so unsolvable that the British Parliament offered a reward of £20,000 (equivalent to £2,870,000 today) to anyone who could solve it. In 2002, the BBC conducted a public poll, and John Harrison was ranked 39th on the list of '100 Greatest Britons'.

Early Life and Career

John Harrison, the eldest of five children, was born on March 24, 1693, in Foulby, near Wakefield in West Yorkshire. His father was a carpenter who worked at the nearby Nostell Priory estate, and there is now a commemorative plaque on the house where the Harrison family likely lived. Around 1700, the family moved to the village of Barrow upon Humber in North Lincolnshire, and John, who helped his father in his work, would repair and assemble clocks in his free time. Legend has it that when he was six years old and suffering from smallpox, John was given a clock to keep him entertained, and he would listen to the ticking and study the moving parts of the mechanism. He also had a great love for music and eventually became the choirmaster of the local parish. Harrison built his first longcase clocks when he was 20 years old. The mechanisms were made entirely of wood, the only material available to a carpenter - and three of Harrison's early works (1713-1717) have survived to this day. In the early 1720s, Harrison received a commission for new tower clocks for Brocklesby Park in North Lincolnshire, and these clocks, made of oak and ironwood, still work to this day. From 1725 to 1728, John and his brother James, also an experienced carpenter, made at least three pendulum clocks, also made of oak and ironwood. According to some experts, these clocks were the most accurate timepieces of their time and precursors to Harrison's marine chronometer. The surviving clocks are now housed in museums in the UK and the United States.

The Marine Chronometer

Harrison was a talented individual who had a wide range of skills, and he constantly used his knowledge and abilities to improve his pendulum clock mechanisms. For example, Harrison invented the compensation of the pendulum by alternating brass and iron rods, which helped eliminate the influence of temperature on the pendulum's movements. Another example of his inventive genius is the so-called grasshopper escapement, a control device that causes the gears to move a certain distance at regular intervals and simultaneously pushes the pendulum. This escapement operated almost without friction and did not require lubrication.

During his work on the marine chronometer, Harrison received financial and advisory support from George Graham, a renowned clockmaker, inventor, and geophysicist. Graham loaned John a large sum of money after their first meeting in 1730, during which the self-taught master explained to Graham how his chronometer worked. They were introduced by royal astronomer Edmond Halley, who also supported Harrison and promoted his work. This support meant a lot to him, as it was difficult for Harrison to convey his ideas to listeners who were unfamiliar with the subject. The work on the first 'marine clock' took Harrison 5 years, after which he embarked on a sea voyage to Lisbon. Upon his return, both captains he traveled with highly praised his invention. Harrison received £500 for further research and continued his work. By 1741, the second, more compact and reliable version of the 'clock' was ready and fully tested, followed by a third version. However, after 17 years of work, the inventor abandoned his ideas and went in a completely new direction. The marine chronometer that brought him fame was completed in 1761, and in his later years, John Harrison lived a very prosperous life.

He died on March 24, 1776, his 83rd birthday, and was buried in Hampstead.