Dictionary of National Biography, 1885-1900/Hartley, David (1732-1813)
HARTLEY, DAVID, the younger (1732–1813), statesman and scientific inventor, son of David Hartley, the philosopher [q. v.], matriculated at Corpus Christi College, Oxford, 6 April 1747, aged 15; proceeded B.A. 14 March 1750, and was fellow of Merton College until his death. He became a student of Lincoln's Inn in 1759; and soon met Benjamin Franklin in London, who became his intimate friend and correspondent. He represented Hull in parliament from 1774 to 1780,and from 1782-4, and attained considerable reputation as an opponent of war with America, and of the African slave trade. It was probably owing to his friendship with Franklin, and to his consistent support of Lord Rockingham, that he was selected by the government to act as plenipotentiary in Paris, where on 3 Sept. 1783 he and Franklin drew up and signed the definitive treaty of peace between Great Britain and the United States of North America. He died at Bath 19 Dec. 1813, in his eighty-second year. His portrait was painted by Romney and has been engraved by J. Walker in mezzotint. Wraxall says that Hartley,'though destitute of any personal recommendation of manner, possessed some talent with unsullied probity, added to indefatigable perseverance and labour.' He adds that his speeches were intolerably long and dull, and that 'his rising always operated like a dinner-bell' (Memoirs, iii. 490).
Hartley's writings are mostly political, and set forth the arguments of the extreme liberals of his time. In 1764 he wrote a vigorous attack on the Bute administration, 'inscribed to the man who thinks himself a minister.' The most important are his 'Letters on the American War,' published in London 1778 and 1779, and addressed to his constituents. 'The road,' he writes, 'is still open to national reconciliation between Great Britain and America. The ministers have no national object in view . . . the object was to establish an influential dominion of the crown by means of an independent American revenue uncontrolled by parliament.' He seeks throughout to vindicate the opposition to the war. In 1794 he printed at Bath a sympathetic 'Argument on the French Revolution,' addressed to his parliamentary electors. In 1859 a number of Hartley's papers were sold in London. Six volumes of letters and other documents relating to the peace went to America and passed into the collection of L. Z. Leiter of Washington; others are in the British Museum (Addit. MSS. 23206 f. 77, 24321 f. 4). In his last years Hartley studied chemistry and mechanics. In 1785 he published 'Account of a Method of Secur ing Buildings and Ships against Fire,' by placing thin iron planks under floors and attaching them to the ceilings, partly to prevent immediate access of the fire, partly to stop the free supply and current of air. He built a house on Putney Heath to verify the efficacy of his invention, and on the occasion of a fire at Richmond House, 21 Dec. 1791, wrote a pamphlet urging the value of his fireplates. Hartley edited his father's wellknown 'Observations on Man,' London, 1791 and (with notes and additions) 1801.
[Foster's Alumni Oxon; Gent. Mag. 1814, pt. i. 95; Stanhope's Hist. vi. 207, vii. 89,208; Martha J. Lamb's History of tiev York, ii. 268 sqq.; Evans's Cat. of Engraved Portraits, vol. ii.; the Private Correspondence of Benjamin Franklin, ed. by W. T. Franklin, Lond. 1817. In vol. ii. are Hartley's letters relating to the peace; Winsor's Hist, of America, vii. 145, 162, 166, viii. 464; Bigelows Life of Franklin, passim.]