THE FIRST CHRONOMETERS

Evening Star, Issue 18817, 16 December 1924, Page 8

THE FIRST CHRONOMETERS

In the Observatory at Greenwich the Astronomer Eoyal has in his care the four first chronometers that were ever made. The first will not go because some parts have been lost. The second has just been repaired and set going by LieutenantCommander Bupcrt T. Could, who is still working on tho third. The fourth, it seems, has never been out of order. This was the instrument which first assured to nn slot- mariners tho means of determining accurately the longitude of their ships. Tho chronometer which Lieutenant-Com-mander Gould has set to work again is keeping time within ten seconds a day—no bad performance for a timepiece made 185 years ago (says tho ‘ Daily Telegraph ’). But the fourth, the latcr-im-pioved chronometer, after 156 days at sea only made a loss of fifteen seconds This was tho instrument that wot: for John Harrison tho prize of £20,00.1 ohered by Parliament for a machine which would determine tho longitude of a ship within thirty miles. When that offer was made, in 1713, John Harrison was a hid of tv only, a Torkslun; carpenter’s son, who had been bred a carpenter. He had hy mature a devotion to clocks and a love of making wheels go round. So he made a clock with wooden wheels which could not be affected by heat and cold. Then ho invented a peudulim so contrived of steel end brass unit the expansion of ore nHal ccunterad >.d that of the other; and by tho time ho was forty-two lie had built a chronometer which was; good enough to be testo.dj and on a voyage lo Lisbon corrected an error in the ship's reckoning of a degree and a-half. For this the Board of Longitude—a committee of experts appointed to deal with tho competitors tor the parliamentary prize- gave him £SOO. Thd machine had taken Harrison six years to make. Twenty-four years later he finished his fourth chronometer, and resolved to put in for the £20,000. Ho was not, it will ho seen, a hurried worker or easily contented with his own performances. This chronometer was officially tested on a voyage to Jamaica and back, which in those days took four months. It was less than two minutes out at tho end—that is, it gave the longitude within eighteen miles. To the layman it seems clear that Harrison had won tho prize. The experts and officials of the Board of Longitude would not certify him the winner. _ He petitioned Parliament, which voted him £5,000, The board would only pay £2,000. He sailed on another voyage of 156 days, and the faithful chronometer determined the long: tude within ton miles. The board pronounced that Harrison deserved the prize, but would not certify that ho had won it. However, Harrison did receive half the £20,000. Tho other half, it seems likely, ho never would have seen but for Ding George 111., who, having had_one of the chronometers tested in his private observatory at Kow, told his Ministers that if they did not see Mr Harrison paid His Majesty would appear at the Bar of the House of Commons and ask for the money. And so, in 1773, a man of eighty, thirtyeight years after his first chronometer had been made, eleven years after his fourth had passed the test prescribed, John Harrison was paid his prize.