In Harrison’s time the Government of the country had become fully alive to the necessity of determining more accurately the longitude at sea. For this purpose they passed an Act in 1714 offering rewards of £10,000, £15,000, and £20,000 to any who should construct chronometers that would determine the longitude within 60, 40, and 30 miles respectively. Harrison applied himself vigorously to the task, and in 1735 went to the Board of Longitude with a watch which he also showed to Halley, Graham, and others. Through their influence he was allowed to proceed in a king’s ship to Lisbon to test it; and the result was so satisfactory that the commissioners gave him £500 to carry out further improvements. Harrison worked at the subject with the utmost perseverance, and, after making several watches, went up to London in 1761 with one which he considered very perfect. His son William was sent on a voyage to Jamaica to test it; and, on his return to Portsmouth in 1762, the watch was found to have lost only 1 minute 54 j seconds. This was surprisingly accurate, as it determined the longitude within 18 miles, and Harrison claimed the full reward of £20,000. After some further trials £10,000 of it was paid to him in 1765, and the remainder in 1767, after he had written such a description of his instrument as would enable other artists to copy it. . Harrison died in 1776, at the age of eighty-two. Hie want of early education was felt by him greatly throughout life. He was unfortunately never able to express his ideas clearly in writing, although in conversation he could give a very precise and exact account of his many intricate mechanical contrivances. He wrote a book entitled Description concerning such Mechanism as will afford α Nice, or True Mensuration of Times,

HARRISON, William Henry (1773-1841), ninth president of the United States, third son of Governor Benjamin Harrison, was bornât Berkeley, Charles City co., Virginia, February 9, 1773. In 1792 he joined the army with the commission of ensign, and in the following year he became lieutenant and acted as aide-de-camp to Wayne in his expedition against the Western Indians. He was promoted to a captaincy in 1795, but resigned in 1797 on being appointed secretary of the North-West Territory. In 1799 he was chosen to represent that territory in congress, and after its division in 1801 he became governor of the new territory of Indiana and superintendent of negotiations with the Indians, over whom, on the breaking out of hostilities in 1811, he gained the important victory of Tippecanoe. In 1813 as major-general and commander of the north-western army he defeated the British forces at the battle of the Thames. In 1814 he concluded a treaty with the North-Western Indians, and in the same year he resigned his commission. He was elected in 1816 member of congress for Cincinnati, in 1819 member of the State senate of Ohio, in 1824 United States senator, and in 1828 minister to Colombia, an office which he held for less than a year, when he retired for a time into private life. By the urgent request of the Whigs he was induced in 1836 to stand for the presidency of the United States, and though unsuccessful, he at the next election in 1840 defeated the same candidate Van Buren by an overwhelming majority, after a canvass memorable for the extraordinary enthusiasm it awakened, and historically important for its introduction of new political methods— many of the most characteristic features of Western elections having their origin in this “Harrison campaign.” He was scarcely spared, however, to enter upon the discharge of his duties as president, dying April 4, 1841, about a month after his inauguration. Harrison published at Cincinnati in 1838 a small treatise on the Indians entitled A Discourse on the Aborigines of the Ohio Valley,