David Buchan, a British explorer, born in 1780, lost at sea about 1837. He obtained a lieutenant's commission in the navy in 1806, and in 1810 commanded a schooner on the Newfoundland station. His admiral, Sir John Duckworth, despatched him to the river Exploit, for the purpose of exploring the interior and opening a communication with the natives. He reached the mouth of the river in January, 1811, and with 34 men and three guides penetrated with the greatest difficulty 130 miles into the country. In 1816 Buchan was promoted to the rank of commander, and in 1818 was appointed to the command of an arctic expedition. The Greenland whalers having reported the sea to be remarkably clear of ice, ' the admiralty fitted out two expeditions that year, one to discover the northwest passage, the other to reach the north pole. The first, intrusted to Capt. Ross and Lieut. Parry, proved unsuccessful. The Dorothea and Trent were selected for the other expedition, under Capt. Buchan and Lieut. Franklin. Among the officers were several who have since distinguished themselves in arctic voyages.

The two vessels sailed in April and reached the place of rendezvous, Magdalena bay, Spitzbergen, about June 1, where they found immense glaciers, and that gigantic barrier of ice which has hitherto frustrated every effort to reach the north pole. Twice they attempted to penetrate it in vain. On June 7 they put to sea, and after several efforts to force a passage were shut up for 13 days in a floe of ice within three miles of land, and with the water so shoal that they could see the bottom. At length the field separated and bore to the south at the rate of three miles an hour. They reached the open sea and took shelter in Fair Haven. On July 6, finding that the ice was again driving northward, they sailed in that direction until the barrier of ice closed upon them, reaching lat. 80° 34' N., which was the most northerly point gained. They attempted in vain to drag the vessels on by ropes and ice anchors, for the current carried them three miles an hour to the southward. The only result of the effort was the loss of several lives. Capt. Buchan then stood over toward the coast of Greenland, but both vessels encountered a heavy gale of wind, which, with the constant shock from floating ice, so disabled the Dorothea that she was in a foundering condition.

They therefore put about, and reached Deptford Oct. 22. In 1823 Buchan was promoted to the rank of captain, and commanded for some time on the Newfoundland station. In 1825 he became high sheriff of that colony, which post he held for several years. He then went on a new expedition into the northern seas, from which he never returned. His ship is supposed to have been burned at sea, but nothing is known with certainty of the fact. In 1839 the admiralty struck his name from the list of living captains. He wrote no account of his voyages, but Capt. Beechey, who served on board the Trent, has supplied the omission. Science is indebted to Buchan for important observations upon marine undercurrents, the variations of the magnetic needle, the temperature of the deep sea as compared with that of the surface, and the compression of the globe at the poles.