As a excellent English icon I thought it would be of interest to write the history of John Harrison (24 March 1693 – 24 March 1776) who was a self-educated English Clockmaker and Yorkshire Carpenter who invented the marine chronometer, a lengthy-sought device in solving the issue of establishing the East-West position or Longitude of a ship at sea, hence revolutionising and extending the possibility of safe long distance sea travel in the Age of Sail.The difficulty was considered so intractable that the British Parliament offered a prize of £20,000 (comparable to £2.87million / €3.65million / .72million in modern currency) for the solution.
John Harrison was born in Foulby close to Wakefield in West Yorkshire the 1st of five young children in his family members. His father worked as a carpenter at the nearby Nostell Priory estate. The residence exactly where he was born bears a blue plaque.
Around 1700, the family moved to the North Lincolnshire village of Barrow upon humber. Following his father’s trade as a carpenter, Harrison built and repaired clocks in his spare time. Legend has it that at the age of six although in bed with smallpox he was given a watch to amuse himself, spending hours listening to it and studying its moving parts.
In 1730 Harrison produced a description and drawings for a proposed marine clock to compete for the
Longitude Prize and went to London looking for financial assistance. He presented his suggestions to Edmond Halley, the Astronomer Royal. Halley referred him to George Graham the country’s foremost clockmaker. He must have been impressed by Harrison, for Graham personally loaned Harrison funds to build a model of his marine clock.
It took Harrison five years to create Harrison Number 1 or H1. He demonstrated it to members of the Royal Society who spoke on his behalf to the Board of Longitude. The clock was the very first proposal that the Board considered to be worthy of a sea trial. In 1736, Harrison sailed to Lisbon on HMS Centurion and returned on HMS Oxford. On their return, both the captain and the sailing master of the Orford praised the style. The master noted that his own calculations had placed the ship sixty miles east of its accurate landfall which had been properly predicted by Harrison making use of H1.
This was not the transatlantic voyage demanded by the Board of Longitude, but the Board was impressed adequate to grant Harrison £500 for further development. Harrison moved on to develop H2, a a lot more compact and rugged version. In 1741, right after 3 years of developing and two of on-land testing, H2 was ready, but by then Britain was at war with Spain in the War of Austrian succession and the mechanism was deemed too crucial to risk falling into Spanish hands. In any event, Harrison suddenly abandoned all function on this second machine when he discovered a serious design flaw in the idea of the bar balances. He was granted yet another £500 by the Board although waiting for the war to end, which he utilised to work on H3. Harrison spent seventeen years working on this third ‘sea clock’ but despite every effort it seems not to have performed precisely as he would have wished. In spite of this, it had proved a quite beneficial experiment. Certainly in this machine Harrison left the globe two enduring legacies — the bimetallic strip and the caged roller bearing.
Following steadfastly pursuing different methods in the course of thirty years of experimentation, Harrison moved to London in the late 1750′s where to his surprise he discovered that some of the watches produced by Graham’s successor Thomas Mudge kept time just as accurately as his large sea clocks. Harrison then realized that a mere watch right after all could be made accurate enough for the task and was a far a lot more practical proposition for use as a marine timekeeper. He proceeded to redesign the idea of the watch as a timekeeping device, basing his design on sound scientific principles.
He had already in the early 1750′s developed a precision watch for his own private use, which was made for him by the watchmaker John Jefferys C. 1752 – 53. This watch incorporated a novel frictional rest escapement and was also most likely the 1st to have both temperature compensation and a going fusee, enabling the watch to continue operating whilst being wound. These features led to the extremely effective efficiency of this “Jefferys” watch and as a result Harrison incorporated them into the design of two new timekeepers which he proposed to build. These had been in the form of a huge watch and yet another of a smaller size but of similar pattern. Nevertheless only the bigger No. 1 (or “H4″ as it often known as) watch appears ever to have been finished. (See the reference to “H6″ below) Aided by some of London’s finest workmen, he proceeded to style and make the world’s initial successful marine timekeeper that for the first time, allowed a navigator to accurately assess his ship’s position in Longitude. Importantly, Harrison showed everybody that it could be done. This was to be Harrison’s masterpiece — an instrument of beauty, resembling an oversized pocket watch from the period. It is engraved with Harrison’s signature, marked Number 1 and dated 1759.
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This very first marine watch (or “Sea watch” as Harrison known as it) is a 5.2″ diameter watch in silver pair circumstances. The movement has a novel kind of escapement which can be classed as a frictional rest type, and superficially resembles the verge escapement with which it is usually incorrectly linked. The pallets of this escapement are each produced of diamond, a considerable feat of manufacture at the time. The balance spring is a flat spiral but for technical causes the balance itself was produced much larger than in a conventional watch of the period. The movement also has centre seconds motion with a sweep seconds hand. The Third Wheel is equipped with internal teeth and has an elaborate bridge similar to the balance cocks of the period. It runs at five beats (ticks) per second, and is equipped with a tiny remontoire. A balance-brake stops the watch half an hour before it is fully run down, in order that the remontoire does not run down also. Temperature compensation is in the form of a ‘compensation curb’ (or ‘Thermometer Kirb’ as Harrison put it). This takes the form of a bimetallic strip mounted on the regulator sector-rack, and carrying the curb pins at the free end. Throughout development of No.1, Harrison abandoned the regulator, but left the regulator disc in spot for æsthetic reasons, and the compensation.
H4 took six years to construct and Harrison, by then 68 years old, sent it on its transatlantic trial in the care of his son, William, in 1761. When HMS Deptford reached Jamaica the watch was five seconds slow, corresponding to an error in longitude of 1.25 minutes, or roughly 1 nautical mile. When the ship returned, Harrison waited for the £20,000 prize but the Board believed the accuracy was just luck and demanded another trial. The Harrisons were outraged and demanded their prize, a matter that eventually worked its way to Parliament, which supplied £5,000 for the design. The Harrisons refused but were eventually obliged to make yet another trip to the Caribbean city of Bridgetown on the island of Barbados to settle the matter.
At the time of the trial, an additional technique for measuring longitude was prepared for testing: the Approach of Lunar Distances. The moon moves quickly enough, some twelve degrees a day, to effortlessly measure the movement from day to day. By comparing the angle among the moon and the sun for the day one left for Britain, the “suitable position” (how it would appear in Greenwich, England at that certain time) of the moon could be calculated. By comparing this with the angle of the moon over the horizon, the longitude could be calculated.
During Harrison’s second trial of “H4″ the Reverend Neville Maskelyne was asked to accompany HMS Tarter and test the Lunar Distances method. When again “H4″ proved nearly astonishingly accurate, keeping time to inside 39 seconds, corresponding to an error in the longitude of Bridgetown of much less than 10 miles (16km). Maskelyne’s measures had been also fairly very good, at 30 miles (48 km), but required considerable function and calculation in order to use. At a meeting of the Board in 1765 the results had been presented, and once once more they could not think it was not just luck. Once once more the matter reached Parliament, which supplied £10,000 in advance and the other half once he turned over the design to other watchmakers to duplicate. In the meantime H4 would have to be turned more than to the Astronomer Royal for lengthy-term on-land testing.
Harrison began working on his H5 while the H4 testing was conducted, with H4 becoming successfully held hostage by the Board. Right after 3 years he had had sufficient Harrison felt “really ill used by the gentlemen who I may have expected better treatment from” and decided to enlist the aid of King George III. He obtained an audience by the King, who was extremely annoyed with the Board. King George tested H5 himself at the palace and soon after ten weeks of day-to-day observations among Could and July in 1772, found it to be accurate to inside one third of one second per day. King George then advised Harrison to petition Parliament for the full prize right after threatening to seem in person to dress them down. In 1773, when he was 80 years old, Harrison received a monetary award in the quantity of £8,750 from Parliament for his achievements, but he by no means received the official award (which was never ever awarded to anybody). He was to survive for just 3 far more years.
In total, Harrison received £23,065 for his function on chronometers. He received £4,315 in increments from the Board of Longitude for his work, £10,000 as an interim payment for H4 in 1765 and £8,750 from Parliament in 1773. This gave him a reasonable income for most of his
