(William), a writer much esteemed and patronised by the literati of his time, was fellow of New-college, Oxford, and had no other income than £40 a year as tutor to one of the duke of Queensberry's sons. In this employment he fortunately attracted the favour of Dr Swift, whose solicitations with Mr St John obtained for him the reputable employment of secretary to lord Raby, ambassador at the Hague, and afterwards earl of Strafford. A letter of his whilst at Utrecht, dated Dec. 16, 1712, is printed in the Dean's works. Mr Harrison, who did not long enjoy his rising fortune, was dispatched to London with the Barrier-treaty; and died Feb. 14, 1712-13. See the Journal to Stella, of that and the following day; where Dr Swift laments his loss with the most unaffected sincerity. Mr Tickell has mentioned him with respect. respect in his Prospect of Peace; in English Poets, Vol. XXVI. p. 113; and Dr Young in the beautiful clove of an Epistle to Lord Lansdowne, Vol. LII. p. 185, most pathetically bewails his loss. Dr Birch, who has given a curious note on Mr Harrison's Letter to Swift, has confounded him with Thomas Harrison, M.A. of Queen's College. In Nichols's Select Collection are some pleasing specimens of his poetry; which, with Woodstock-Park in Dodley's Collection, and an Ode to the Duke of Marlborough, 1707, in Duncombe's Horace, are all the poetical writings that are known of this excellent young man; who figured both as a humorist and a politician in the fifth volume of the Tatler, of which (under the patronage of Bolingbroke, Henley, and Swift) he was professedly the editor. See the Supplement to Swift.—There was another William Harrison, author of The Pilgrim, or the happy Convert, a Pastoral Tragedy, 1709.

Harrison (John), a most accurate mechanic, the celebrated inventor of the famous time-keeper for ascertaining the longitude at sea, and also of the compound, or, as it is commonly called, the gridiron pendulum; was born at Foulby, in the parish of Wraby, near Pontefract in Yorkshire, in 1693. The vigour of his natural abilities, if not even strengthened by the want of education, which confined his attention to few objects, at least amply compensated the deficiencies of it; as fully appeared from the astonishing progress he made in that branch of mechanics to which he devoted himself. His father was a carpenter, in which profession the son assisted; occasionally also, according to the miscellaneous practice of country artists, surveying land, and repairing clocks and watches. He was, from his early childhood, attached to any machinery moving by wheels, as appeared while he lay sick of the small-pox about the fifth year of his age, when he had a watch placed open upon his pillow to amuse himself by contemplating the movement. In 1700, he removed with his father to Barrow in Lincolnshire; where, though his opportunities of acquiring knowledge were very few, he eagerly improved every incident from which he might collect information; frequently employing all or great part of his nights in writing or drawing; and he always acknowledged his obligations to a clergyman who came every Sunday to officiate in the neighbourhood, who lent him a MS. copy of professor Saunderson's Lectures; which he carefully and neatly transcribed, with all the diagrams. His native genius exerted itself superior to these solitary disadvantages; for in the year 1726, he had constructed two clocks, mostly of wood, in which he applied the escapement and compound pendulum of his own invention; these surpassed everything then made, scarcely erring a second in a month. In 1728, he came up to London with the drawings of a machine for determining the longitude at sea, in expectation of being enabled to execute one by the board of longitude. Upon application to Dr Halley, he referred him to Mr George Graham; who, discovering he had uncommon merit, advised him to make his machine before he applied to the board of longitude. He returned home to perform this task; and in 1735 came to London again with his first machine; with which he was sent to Lisbon the next year for a trial of its properties. In Harrison, this short voyage, he corrected the dead reckoning about a degree and a half; a success that proved the means of his receiving both public and private encouragement. About the year 1739, he completed his second machine, of a construction much more simple than the former, and which answered much better; this, though not sent to sea, recommended Mr Harrison yet stronger to the patronage of his private friends and of the public. His third machine, which he produced in 1749, was still less complicated than the second, and superior in accuracy, as erring only three or four seconds in a week. This he conceived to be the ne plus ultra of his attempts; but in an endeavour to improve pocket-watches, he found the principles he applied to surpass his expectations so much, as to encourage him to make his fourth time-keeper, which is in the form of a pocket watch, about six inches diameter. With this time-keeper his son made two voyages, the one to Jamaica, and the other to Barbadoes; in both which experiments it corrected the longitude within the nearest limits required by the act of the 12th of queen Anne; and the inventor therefore, at different times, though not without infinite trouble, received the proposed reward of 20,000l. These four machines were given up to the board of longitude. The three former were not of any use, as all the advantages gained by making them were comprehended in the last; they were worthy, however, of being carefully preserved as mechanical curiosities, in which might be traced the gradations of ingenuity executed with the most delicate workmanship; whereas they now lie totally neglected in the royal observatory at Greenwich. The fourth machine, emphatically distinguished by the name of The time-keeper, has been copied by the ingenious Mr Kendal; and that duplicate, during a three years circumnavigation of the globe in the southern hemisphere by captain Cook, answered as well as the original. The latter part of Mr Harrison's life was employed in making a fifth improved time-keeper on the same principles with the preceding one; which, at the end of a ten weeks trial, in 1772, at the king's private observatory at Richmond, erred only 4½ seconds. Within a few years of his death, his constitution visibly declined; and he had frequent fits of the gout, a disorder that never attacked him before his 77th year; he died at his house in Red-Lion Square, in 1776, aged 83. The recluse manner of his life in the unremitting pursuit of his favourite object, was by no means calculated to qualify him as a man of the world; and the many discouragements he encountered in soliciting the legal reward of his labours, still less disposed him to accommodate himself to the humours of mankind. In conversing on his profession, he was clear, distinct, and modest; yet, like many other mere mechanics, found a difficulty in delivering his meaning by writing; in which he adhered to a peculiar and uncouth phraseology. This was but too evident in his Description concerning such mechanism as will afford a nice or true mensuration of time, &c. 8vo. 1775; which his well-known mechanical talents will induce the public to account for from his unacquaintance with letters, from his advanced age, and attendant mental infirmities; among Hart, mong which may be reckoned his obstinate refusal to accept of any assistance whatever in this publication.

This small work includes also an account of his new musical scale; or mechanical division of the octave, according to the proportion which the radius and diameter of a circle have respectively to the circumference. He had in his youth been the leader of a distinguished band of church-singers; had a very delicate ear for music; and his experiments on sound, with a most curious monochord of his own improvement, are reported to have been not less accurate than those he was engaged in for the mensuration of time.