Finding his way back to South Australia he was commissioned by a merchant to buy a new vessel in Sydney, and as master of the Hope returned with cattle. He seems to have made a voyage from England between 26 Feb. and 1 July 1838 with the Henry Porcher (Stephens, South Australia), and it was probably not till December 1838 that he established the headquarters of his whale fishery at Encounter Bay, where he was made harbour master. He now first turned his attention to shore concerns, and became in November 1840 director of the Adelaide Auction Company. The crisis of 1842 and the following year brought all business to a standstill; in 1843 he took to the sea again, and sailed for England on the Augustus, of which he owned two thirds; he seems to have had a great reputation as a seaman, and was known as 'Captain' Hart to the end of his life.
After two or three voyages to the old country and back, Hart finally gave up the sea about 1846, and devoted himself to commercial pursuits, eventually settling down to the management of the flour mills which connected his name with one of the best brands of Australian flour. He also started the Mercantile Marine Insurance Company, and was a director of the Union Bank of Australia.
Hart first entered political life when he supported the indignation meetings against Governor Robe's land policy; he was member for the Victoria district in the old legislative council of 1851, and, after a visit to England in 1853, returned to take part in the discussions on reform in 1854 and 1855. He was elected as member for Port Adelaide in the first House of Assembly on 25 March 1857. In August he was treasurer for ten days under John Baker, and again held the post under (Sir) Reginald Davies Hanson from 30 Sept. 1857 to 12 June 1858; he resigned because of a considerable difference of opinion with his colleagues. In 1859 he was again in England intent upon starting the Northern Mining Company for operations in the northern territorities; on his return he found that his conduct in regard to mining leases had been attacked, and he demanded the appointment of a select committee which fully exonerated him. In July 1863 he was colonial secretary under Francis S. Button for a few days, and then from 15 July 1864 to 22 March 1865 under (Sir) Henry Ayers and (Sir) Arthur Blyth [q. v. Suppl.] successively.
On 23 Oct. 1865 Hart was called upon to form his first ministry, which lasted till 28 March 1866; he then went to England for a year. In 1868 he was elected for Light; the crucial question of land-law reform was before the colony; it seemed impossible to get a strong ministry together. Hart was premier from 24 Sept. to 13 Oct. 1868, but failed to meet the crisis. Ayers followed, and had to go very quickly; but the next premier, Henry B. T. Strangways, succeeded in passing the land act known by his name. On 3 May 1870 Hart again became premier. This was his chief administration; his first act was to carry through the already projected overland telegraph line to the northern territory; on the question of the development of this territory he had always been an authority. He also tried to continue the improvement of the land law, but his bill was lost in the assembly by the speaker's casting vote. His financial policy was sound and his tariff act much commended. He resigned on an adverse vote on 10 Nov. 1871. He was not again in office; on 28 Jan. 1873 he died suddenly in the act of addressing a meeting of the Mercantile Marine Insurance Company. He was buried near Adelaide, where he resided.
Hart was a cautious man of sound judgment, a plain straightforward speaker; in public life financial and educational reform was his chief watchword; he first advocated consolidation of the South Australian debt. He was made C.M.G. in 1870.
He was married and left a large family.
[South Australian Register, 30 Jan. (Suppl.) and 31 Jan. 1873; Mennell's Dict. of Australasian Biography; South Australian Blue-books; Hodder's Hist, of South Australia, ii. 4 and 15.]
HAUGHTON, SAMUEL (1821–1897), man of science, born in Carlow on 21 Dec. 1821, was son of James Haughton [q. v.], of whom he published a 'Memoir' in 1877. He was educated at first at a school in Carlow and, at the age of seventeen, entered Trinity College, Bublin. Here he obtained first gold medal in mathematics (1843), and, six months afterwards, was a successful candidate at the fellowship examination (1844). He graduated B.A. in 1844 and M.A. in 1852. He was ordained deacon in 1846 and priest in 1847.
After obtaining a fellowship Haughton's attention, probably in consequence of his friendship with James McCullagh [q. v.], professor of mathematics at Trinity, was at first directed to mathematical physics. His principal papers on this subject were: 'On the Laws of Equilibrium and Motion of Solid and Fluid Bodies' (Camb. and Dubl. Math. Journal, i. 1846); 'On a Classification of Elastic Media, and the Laws of Plane