John, the inventor of the gridiron pendulum, an ingenious recoil escapement, and the going fusee, was born in 1693 at Faulby, near Pontefract in Yorkshire. His father was a carpenter, and the son wrought for some time at the father's trade, eking out his gains by occasionally surveying land, and repairing clocks and watches. In 1700 he removed with his father to Barrow in Lincolnshire, and spent much of his time in devising improvements on the machinery of watches. In 1714 government had offered a reward of ten, fifteen, and twenty thousand pounds respectively for a method of determining the longitude at sea within 60, 40, or 30 miles. In 1735 Harrison presented himself before the Board of Longitude at London, with an instrument, which he submitted for inspection to Halley, Grahame, and others. At their instance Harrison was sent in a royal ship to Lisbon to test it, and by it he corrected the reckoning a degree and a half. The commissioners rewarded him with L500 to enable him to carry on his experiments, which, after some failures, resulted in his producing an instrument so accurate that in the course of a voyage to Jamaica and back it was found to have gone wrong by less than two minutes. Harrison accordingly claimed the reward of L20,000, which, after a second voyage to Jamaica, and other tests, was finally paid down to him in 1767. Harrison died in 1776 at the age of eighty-two. Till his death he never got over the defects of his early training. He could express himself with perfect clearness and precision on the subject of his art, but, like most uneducated men, he utterly failed when he tried to express his thoughts in writing. This is manifested in his