1911 Encyclopædia Britannica/Sedgwick, Adam

From Wikisource
Jump to navigation Jump to search
22305211911 Encyclopædia Britannica, Volume 24 — Sedgwick, Adam

SEDGWICK, ADAM (1785–1873), English geologist, was born on the 22nd of March 1785 at Dent in Yorkshire, the second son of Richard Sedgwick, vicar of the parish. He was educated at the Grammar Schools of Dent and Sedbergh, and at Trinity College, Cambridge, where he graduated B.A. as fifth wrangler in 1808, and two years later was elected a Fellow of his college. For several years he was occupied as private tutor and afterwards as assistant mathematical tutor at Trinity College. In 1818 he was admitted to priests' orders. He had at this time paid no serious attention to geology. As a lad he had collected fossils from the Mountain Limestone near Dent, and in 1813 he had visited the mines near Furness and Coniston. Nevertheless, when the Rev. John Hailstone retired in 1818 from the post of Woodwardian professor of geology, Sedgwick applied for the vacancy, and was so strongly supported by his college as a man of talent that he was elected by a large majority. He now took up the study of geology with intense zeal, traversed large areas in the south of England, and, becoming acquainted with W. D. Conybeare, regarded him as his master in geology. It is astonishing with what rapidity he grasped the principles of stratigraphical geology and the relationships of rocks in the field. In papers read before the Cambridge Philosophical Society, 1820–1821, on the structure of parts of Devonshire and Cornwall, he made observations of exceptional interest and value. Of this society in 1819 he had been one of the founders with J. S. Henslow. Every year for a long period now brought its season of field-work. Sedgwick dealt with the geology of the Isle of Wight, and with the strata of the Yorkshire coast (in papers published in the Annals of Philosophy, 1822, 1826); and he examined the rocks of the north of Scotland with Murchison in 1827. He contributed an important essay On the Geological Relations and Internal Structure of the Magnesian Limestone to the Geological Society of London (1828). As early as 1822 he had begun to make a detailed geological map of the older rocks of the Lake District; he continued these researches whereby the main structure of this mountain region was first unravelled, in succeeding years; and the principal results were brought before the Geological Society (1831–1836). Meanwhile he was elected president of the Geological Society in 1829–1830, and in 1831 he commenced field-work in North Wales. His chief attention was now concentrated on the older rocks of England and Wales. Murchison began the task of unravelling the structure of the older rocks on the Welsh borders in the same year. They had intended to start together, but the arranger rents fell through, and thus they began their labours independently and from opposite sides of the principality. Eventually Sedgwick founded the Cambrian system for the oldest group of fossiliferous strata, and Murchison the Silurian system for the great group immediately below the Old Red Sandstone. Their systems were found to overlap—Sedgwick's Upper Cambrian and Murchison's Lower Silurian being practically equivalent. Hence arose a painful controversy that has only of late years been terminated by the adoption of Professor C. Lapworth's term Ordovician in place of the Upper Cambrian of Sedgwick and the Lower Silurian of Murchison.

Sedgwick was ever actively interested in the work of his university. His famous Discourse on the Studies of the University of Cambridge, delivered in 1832, was published in expanded form in 1833; it reached a fifth edition in 1850. The studies were reviewed under the headings of (1) The laws of nature, (2) Ancient literature and language, and (3) Ethics and metaphysics; and the volume had so grown that it ultimately consisted of 442 pages of preface, or preliminary dissertation on the history of creation, with arguments against the transmutation of species, and an essay on the evidences of Christianity; the discourse occupied 94 pages; and there was an appendix of notes, &c., that filled 228 pages.

In 1833 Sedgwick was president of the British Association at the first Cambridge meeting, and in 1834 he was appointed a canon of Norwich. In 1836 with Murchison he made a special study of the Culm-measures of Devonshire, which until that time had been grouped with the greywacke, and together they demonstrated that the main mass of the strata belonged to the age of the true Coal Measures. Continuing their researches into the bordering strata they were able to show in 1839, from the determinations of William Lonsdale, that the fossils of the South Devon limestones and those of Ilfracombe and other parts of North Devon were of an intermediate type between those of the Silurian and Carboniferous systems. They therefore introduced the term Devonian for the great group of slates, grits and limestones, now known under that name in West Somerset, Devon and Cornwall. These results were published in the great memoir by Sedgwick and Murchison, “On the Physical Structure of Devonshire” (Trans. Geol. Soc., 1839). Of later published works it will be sufficient to mention A Synopsis of the Classification of the British Palaeozoic Rocks (1855), which contained a systematic description of the fossils by F. McCoy. Also the preface by Sedgwick to A Catalogue of the collection of Cambrian and Silurian Fossils contained in the Geological Museum of the University of Cambridge, by J. W. Salter (1873).

The Wollaston Medal of the Geological Society was awarded to Sedgwick in 1851, and the Copley Medal of the Royal Society in 1863. He continued to lecture until 1872, when ill-health rendered necessary the appointment of a deputy (Professor J. Morris). He died at Cambridge on the 27th of January 1873.

In 1865 the senate of the university received from A. A. Van Sittart the sum of £500 “for the purpose of encouraging the study of geology among the resident members of the university, and in honour of the Rev. Adam Sedgwick.” Thus was founded the Sedgwick prize to be given every third year for the best essay on some geological subject. The first Sedgwick prize was awarded in 1873. On the death of Sedgwick it was decided that his memorial should take the form of a new and larger museum. Hitherto the geological collections had been placed in the Woodwardian Museum in Cockerell's Building. Through the energy of Professor T. McK. Hughes (successor to Sedgwick) the new building termed the Sedgwick Museum was completed and opened in 1903.

See the Life and Letters, by John Willis Clark and Thomas McKenny Hughes (1890).