Horner, Leonard

(b. Edinburgh, Scotland, 17 January 1785; d London, England, 5 March 1864)

geology.

Horner was the third son of John Horner, an Edinburgh textile merchant, and younger brother of Francis Horner, the Whig politician and a founder of the Edinburgh Review. After attending Edinburgh University, he moved to London in 1804 as a partner in his father’s business. He joined the Geological Society of London in 1808, soon after its foundation, and served as secretary from 1810 to 1814 and as president in 1845–1847 and 1860–1862. He was elected to the Royal Society of London in 1813.

In 1817 Horner returned to Edinburgh; and in 1821 he founded there a school of arts, one of the earliest examples of the Mechanics’ Institute movement. In 1827 he was called to the newly founded University College, London, where he served as warden until 1831, supervising the formative years of the first English university institution to give a major place to scientific subjects. After two years’ residence in Bonn for the sake of his health, Horner returned to England and was appointed to serve on the commission on the employment of children in factories; under the subsequent Factory Act (1833) he was for many years an inspector of factories. His concern as a social reformer is also reflected in published works on working-class education and on working conditions in factories. Horner married Anne Lloyd in 1806; their eldest child, Mary, married the geologist Charles Lyell in 1832.

Horner’s work in promoting science-based education at all social levels was more important for the development of nineteenth-century science than was his original scientific work, although the latter was far from negligible. Horner had attended the mathematics lectures of John Playfair at Edinburgh and was greatly influenced by Playfair’s geology. His two earliest papers, on the Malvern Hills (1811) and an area of Somerset (1816) in Southwestern England, show meticulous description allied to cautious Huttonian theorizing; they were written at a time when “geology” was only just beginning to become clearly distinct from “mineralogy.” His presidential addresses to the Geological Society in 1846 and 1847 show strong sympathy with the Playfairian Principles of Geology of his son-in-law Lyell and at the same time are masterly reviews of the current progress of the science. In the 1850’s Horner had the support of the Royal Society in an ambitious scheme for excavating the Nile silt around the bases of two Egyptian monuments of known historic date; he hoped to estimate the mean rate of deposition, in order to link the historical time scale to the relative time scale of geology. Although his work was criticized, he believed it gave strong evidence that even the recent geological period had lasted not less than 13,500 years and that fragments of pottery indicated almost as great an antiquity for the human race. He reiterated this conclusion in his last address to the Geological Society (1861), anticipating Lyell’s Antiquity of Man (1863); in the same address he also gave a warm recommendation to Darwin’s Origin of Species (1859).

BIBLIOGRAPHY

Horner’s principal scientific publications are “On the Mineralogy of the Malvern Hills,” in Transactions of the Geological Society of London, 1 (1811), 281–321; “Sketch of the Geology of the South-Western Part of Somersetshire,” ibid., 3 (1816), 338–384; “On the Geology of the Environs of Bonn,” ibid., 2nd ser. 4 , pt. 2 (1836), 433–481; “Anniversary Address[es] of the President,” in Quarterly Journal of the Geological Society of London, 2 (1846), 145–221; 3 (1847), xxii–xc; 17 (1861), xxii–lxxii; and “An Account of Some Recent Researches Near Cairo, Undertaken With a View of Throwing Light Upon the Geological History of the Alluvial Land of Egypt,” in Philosophical Transaction of the Royal Society, 145 (1855), 105–138; 148 (1858), 53–92. His daughter Mary Horner Lyell edited a valuable collection of correspondence in her Memoir of Leonard Horner, F.R.S., F.G.S., Consisting of Letters to His Family and From Some of His Friends, 2 vols. (London, 1890).

M. J. S. Rudwick