Page:Dictionary of National Biography volume 20.djvu/59

 1817 in the Eridanus with Captain King in the North Sea and Channel fleets. In 1817 he joined Captain Hickey in the Blossom, with whom he served until 1819. When the Blossom visited the Columbia River with the commissioners to establish the boundary line between Great Britain and the United States, he surveyed the river's mouth. When in the Creole with Commodore Bowles in 1819 he made a useful survey of the north shore of the river La Plata. In 1820 he accompanied Captain Basil Hall in the Conway in his voyage to South America, and assisted him greatly in his pendulum and other observations. His next appointment, in 1823, was to the Griper, Captain Clavering, on her voyage with Captain Sabine to the coasts of Greenland and Norway, and on the return of this ship in 1824 he received full lieutenant's rank, being also elected F.R.S. on 6 May. As astronomer to the expedition Foster sailed with Sir Edward Parry on his third voyage of north-western discovery, May 1824 to October 1825, and again accompanied him, April–September 1827, in his attempt to reach the north pole. At Port Bowen and other stations within the Arctic circle he made, with the assistance of Parry and others, an extensive series of observations upon the diurnal variation, diurnal intensity of the magnetic needle, and upon other subjects connected with terrestrial magnetism and astronomical refractions, which formed an entire fourth part of the ‘Philosophical Transactions’ for 1826, and was printed at the expense of the board of longitude. For these papers he received the Copley medal of the Royal Society, 30 Nov. 1827, and in half an hour afterwards the rank of commander. Another valuable paper contributed by him to the same serial was ‘A Comparison of the Changes of Magnetic Intensity throughout the Day in the Dipping and Horizontal Needles at Treurenburgh Bay in Spitzbergen’ (Phil. Trans. cxviii. 303–11). On 12 Dec. 1827 he was appointed to the command of the Chanticleer, a sloop sent out by the government to the South Seas at the suggestion of the Royal Society, in order to determine the specific ellipticity of the earth by a series of pendulum experiments at various places, and to make observations on magnetism, meteorology, and the direction of the principal ocean currents. Foster sailed from Spithead 27 April 1828. He commenced the pendulum experiments on Rat Island, Montevideo. He rounded Cape Horn on 27 Dec., and on 5 Jan. 1829 observed Smith's Island, one of the New South Shetland group. Two days later he touched at Trinity Island, which he christened ‘Clarence Land,’ and of which he took possession in the name of Great Britain, not being aware of its previous discovery in 1599 by Dirck Gherritz, and of its position in most of the old charts by the name of ‘Gherritz Land.’ From 9 Jan. to 4 March he remained at an island on these coasts, to which he gave the name of ‘Deception Island,’ busied with astronomical and geodesic observations, then returned to Cape Horn 25 March, and anchored in St. Martin's Cove. Here he was joined on 17 April by Captain King in the Adventure, employed on a survey of the islands adjacent. Leaving Cape Horn on 24 May Foster bore away for the Cape of Good Hope, which he reached by 16 July, and where he stayed until 13 Dec. He then visited St. Helena, and afterwards various South American ports, arriving at Porto Bello on 22 Dec. 1830. Here he wished to measure the difference of longitude across the isthmus of Panama by means of rockets. After various preparations and one failure, he left for Panama on 28 Jan. 1831, to make the final experiment. It proved successful, and the meridian distance between Panama and Chagres having been thus measured, Foster, in high spirits, embarked in a canoe at Cruces on 5 Feb. to return down the river Chagres. In the evening he was sitting upon the awning when it gave way, and he fell into the river and was drowned. His remains were recovered on 8 Feb. and buried on the river bank, nearly halfway between Palamatio Viejo and Palamatio Nueva. A monument marks the spot. A simple tablet was also raised to his memory by the officers of the Chanticleer in the port of San Lorenzo at Chagres; another monument to him is in the north aisle of Wood Plumpton Church. ‘There were few officers in the service whose minds could have been more highly cultivated than Foster's,’ writes one of his comrades in the Arctic expedition (United Service Journal, 1835, pt. ii. pp. 83–4). Foster's notebook, containing all his observations since leaving Porto Bello, was stolen from his body by the canoe-men, but he left an immense mass of observations of various kinds, which the admiralty confided partly to the Royal Society and partly to the Astronomical Society. A report on the pendulum experiments of Foster was drawn up by Francis Baily, the president of the Astronomical Society, and inserted in vol. vii. of their ‘Memoirs;’ it was also printed by the admiralty. The preparation of the report on his chronometrical observations was entrusted to Dr. J. L. Tiarks, F.R.S. These, with other valuable papers, form the appendix to the ‘Narrative of a Voyage to the Southern Atlantic Ocean, in the years 1828, 29, 30, performed in H. M.