(b. Orkney Islands, Scotland, 1773; d. London, England, 26 December 1844), geology.
Webster came to London early in life and trained as an architect. In 1799 he was appointed clerk of the works at the newly founded Royal Institution and built its famous lecture theater. Later, taking up geology as a profession, he became curator, draughtsman, librarian, secretary, and editor to the Geological Society (founded in 1807). Leaving this employment in 1827, he took up public lecturing and in 1841 became the first professor of geology at University College.
Webster’s original geological work was entirely concerned with the stratigraphy of the uppermost Jurassic, the Cretaceous, and the Tertiary rocks of southern England. In his chief paper (1814) Webster recorded a highly important piece of research, perhaps the first of its kind (being detailed and thoroughly scientific) on the geology of a British region. He described the characters of the Tertiary strata of southeast England, and particularly those of the Oligocene (later so called) of the Isle of Wight, in which he recognized an alternation of marine and freshwater formations. Webster compared all of these Tertiary strata with those that had been recently described in the Paris Basin by Cuvier and Brongniart. Of even greater importance was his survey of the Isle of Wight (Cretaceous and Tertiary) and “Isle” of Portland (mostly Jurassic and Cretaceous), with the production of one of the first geological maps of any part of Britain and one that was on a larger scale and more accurate than anything previously attempted. The geology of this classic region was almost completely unknown before Webster sketched, in words and picture, the features of its structure (essentially a monocline with vertical limb) in a series of lucid, forceful, and entertaining “letters” (1816). Unfortunately for the progress of geological knowledge. his duties at the Geological Society pressed so heavily upon him that he was prevented from undertaking any further large-scale investigations.
I. Original Works. Webster’ autobiography, which was probably written about 1837, is in MS in the library of the Royal Institution, London. Of Webster’s ten publications, which are enumerated in Challinor (1964), the following publications are most important: “On the Freshwater Formations of the Isle of Wight, With Some Observations on the Strata Over the Chalk in the Southeast Part of England,” in Transactions of the Geological Society of London, 2 (1814), 161–254; and “Geological Observations on the Isle of Wight and Adjacent Coast of Dorsetshire in a Series of Letters.” in Sir Henry Englefield, The Picturesque Beauties of the Isle of Wight (London, 1816), 117–238.
II. Secondary Literature. On Webster and his work, see G. S. Boulger, Dictionary of National Biography, LX (1899), 126; J. Challinor, “Thomas Webster’s Letters on the Geology of the Isle of Wight, 1811-1813,” in Proceedings of the Isle of Wight Natural History and Archaeological Society , 4 (1949), 108–122; “Some Correspondence of Thomas Webster, Geologist,” in Annals of Science, 17 (1961), 175–195; 18 (1962), 147–175; 19 (1963), 49–79, 285–297; 20 (1964), 59–80, 143–164; N. Edwards, “Thomas Webster (circa1772-1844).” in Journal of the Society of Bibliography of Natural History, 5 (1971), 468–473; E. Forbes, The Tertiary Fluvio-Marine Formation of the Isle of Wight one of the Memoirs of the Geological Survey of Great Britain (1856); K. D. C. Vernon, “The Foundation and Early Years of the Royal Institution,” in Proceedings of the Royal Institution of Great Britain, 39 (1963), 364–402; and H. B. Woodward, History of the Geological Society of London (London, 1908), passim.