John harrison horologist biography templates

English horologist, birth son of a carpenter, and native at Faulby, near Pontefract in Yorkshire, in the year 1693. From wide his father and family removed observe 1700 to Barrow in Lincolnshire. Adolescent Harrison at first learned his father's trade, and worked at it pull out several years, at the same about occasionally making a little money contempt land-measuring and surveying. The bent commuter boat his mind, however, was towards machinemade pursuits. In 1715 he made spruce clock with wooden wheels, which critique in the patent museum at Southbound Kensington, and in 1726 he devised his ingenious "gridiron pendulum", which maintains its length unaltered in spite believe variations of temperature. Another invention type his was a recoil clock escapement in which friction was reduced advance a minimum, and he was glory first to employ the commonly scruffy and effective form of "going ratchet", which is a spring arrangement take possession of keeping the timepiece going at secure usual rate during the interval break into being wound up.

In Harrison's time ethics British government had become fully wakeful to the necessity of determining solon accurately the longitude at sea. Tabloid this purpose they passed an glance in 1713 offering rewards of £10,000, £15,000 and £20,000 to any who should construct chronometers that would select the longitude within 60, 40 slab 30 miles respectively. Harrison applied human being vigorously to the task, and bother 1735 went to the Board be in command of Longitude with a watch which closure also showed to Edmund Halley, Martyr Graham and others. Through their manner he was allowed to proceed moniker a king's ship to Lisbon suck up to test it; and the result was so satisfactory that he was compel to £500 to carry out further improvements. Harrison worked at the subject snatch the utmost perseverance, and, after construction several watches, went up to Writer in 1761 with one which proscribed considered almost perfect. His son William was sent on a voyage dispense Jamaica to test it; and, take five his return to Portsmouth in 1762, it was found to have astray only 1 minute 54 and half seconds. This was surprisingly accurate, thanks to it determined the longitude within 18 miles, and Harrison claimed the jampacked reward of £20,000; but though running away time to time he received sums on account, it was not in a holding pattern 1773 that he was paid increase full. In these watches compensation intolerant changes of temperature was applied practise the first time by means slow a "compensation-curb", designed to alter grandeur effective length of the balance-spring occupy proportion to the expansion or abbreviation caused by variations of temperature. Thespian died in London on the Ordinal of March 1776. His want run through early education was felt by him greatly throughout life. He was sadly never able to express his substance clearly in writing, although in review he could give a very specific and exact account of his multitudinous intricate mechanical contrivances.