Dictionary of National Biography, 1885-1900/Welsh, John
WELSH, JOHN (1824–1859), meteorologist, eldest son of George Welsh of Craigenputtock, was born at Boreland in the stewartry of Kirkcudbright on 27 Sept. 1824. His father, who was ‘extensively engaged in agriculture,’ died in 1835, and his mother settled at Castle Douglas, where Welsh received his early education. In November 1839 he entered the university of Edinburgh with a view to becoming a civil engineer, and studied under Professors Philip Kelland [q. v.], James David Forbes [q. v.], and Robert Jameson [q. v.] In December 1842 Sir Thomas Makdougall-Brisbane [q. v.], on the advice of Forbes, engaged Welsh as an observer at his magnetical and meteorological observatory at Makerstoun under John Allan Broun [q. v.], then director. In 1850 Welsh, being anxious to obtain some other post, was recommended by Brisbane to Colonel William Henry Sykes [q. v.], chairman of the committee of the British Association which managed the Kew Observatory, and he was appointed assistant to (Sir) Francis Ronalds [q. v.], who was honorary superintendent. Welsh read at the Ipswich meeting of the association in October 1851 an elaborate report on Ronalds's three magnetographs. Welsh also presented and described two sliding-rules for reducing hygrometrical and magnetic observations. In 1852 he read an important report on the methods used in graduating and comparing standard instruments at the Kew Observatory. Since this date the verification of thermometers and barometers for construction of these instruments has been regularly undertaken at Kew.
Welsh now succeeded Ronalds, who had resigned, as superintendent of the observatory. On 17 Aug., 26 Aug., 21 Oct., and 10 Nov. 1852 he made, under the auspices of the Kew committee, four ascents from Vauxhall, with the assistance of Charles Green [q. v.], in his balloon the Great (or Royal) Nassau, in order to make meteorological observations, of which a detailed description is given in the ‘Philosophical Transactions’ for 1853, p. 310.
In March and May 1854 he made for the committee an investigation on the ‘pumping’ of marine barometers. In 1855 Welsh went to Paris to supervise, at the exhibition of that year, the exhibit of magnetic and meteorological instruments used at Kew. In 1856 he began at Kew a series of monthly determinations of absolute magnetic intensity and magnetic dip with instruments provided by General (Sir) Edward Sabine [q. v.] In the same year Welsh was directed to construct self-recording magnetic instruments on the models devised originally by Ronalds and improved by himself.
In 1857 he was elected F.R.S. In the same year the Kew committee having decided on a magnetic survey of the British islands, Welsh was appointed to undertake the ‘North British’ division, and spent part of the summers of 1857 and 1858 on this work. But during the winter of 1857–8 Welsh had suffered from lung disease, and this increased during the following year. Acting under medical advice, he spent the winter of 1858–9, accompanied by his mother, at Falmouth, and died at that place on 11 May 1859.
[Proceedings of the Royal Society, vol. x. pp. xxxiv (obituary) and xxxix passim (Scott's Hist. of the Kew Observatory, also published separately); Welsh's own papers; Brit. Assoc. Reports, 1850–59.]