Conybeare, William Daniel

(b. London, England, June 1787; d, Llandaff, Wales, 12 August 1857),

geology.

Conybeare was the younger son of Rev. William Conybeare, rector of St. Botolph’s, Bishopsgate, London. He was educated at Westminster School and Christ Church, Oxford. On marrying in 1814, he took a curacy in Suffolk, became rector of Sully (Glamorganshire) in 1822, took his family living as vicar of Axminster (Devon) in 1836, and became dean of Llandaff in 1845. An early member (1811) of the Geological Society of London, he was elected a fellow of the Royal Society in 1832. In addition to his scientific work he published works on biblical and patristic theology and was Bampton lecturer at Oxford in 1839.

Conybeare was one of the most active early members of the “Oxford school” of geology and was a close associate of William Buckland. He was one of the most able British exponents of the synthesis of progressionism and catastrophism, which dominated geology in the 1820’s and 1830’s.

His most important single work was his great enlargement and improvement of William Phillips’ compilation of English stratigraphy. This created a synopsis of stratigraphical knowledge that was at the time unrivaled in detail and accuracy (1). In the general introduction to the Outlines, Conybeare considered the range of “actual causes” but regarded them as inadequate to explain such phenomena as the “diluvium” (glacial drift) and the form of valleys; for these he proposed diluvial explanations, although without stressing any concordance with the scriptural Flood. The Outlines described British stratigraphy back to the Carboniferous and was termed “Part I”; Adam Sedgwick was to have assisted Conybeare with a second volume on the earlier strata, but it was never published. Conybeare collaborated with Buckland in a stratigraphical memoir on the coal fields around Bristol (2) that was much admired as a model of clear description and reasoned inference; he also attempted a general correlation with Continental stratigraphy and tectonics (3).

Some fragmentary fossil remains from the Lias of Lyme Regis prompted Conybeare’s main work in paleontology. From a detailed comparison of normal reptiles and the highly aberrant Ichthyosaurus, he inferred that the new remains were intermediate in anatomy. This reconstruction of the Plesiosaurus, which excited great interest, was later confirmed by the discovery of a more complete skeleton (4). His functional anatomy clearly was modeled on Cuvier; but he stressed the interest of intermediate forms as “links in the chain” of organisms, showing, however, by an explicit rejection of Lamarck’s transmutation, that the chain was that of an échelle des êtres, not an evolutionary series.

Conybeare’s exposition of the catastrophist-progressionist synthesis was both more able and more moderate than that of Buckland. He argued in 1829 that the fluvial erosion postulated by Lyell for the valleys of central France was inadequate to explain the form of the valleys of the Thames and other British rivers and suggested that the more powerful agency of a “diluvial” episode was required to account for them (5). He defended the progressionist viewpoint on directional climatic change against the criticisms of John Fleming (6) and later (1830–1831) wrote one of the most important defenses of the whole progressionist synthesis in answer to the more radical attack of Lyell’s Principles of Geology (7). The moderate and flexible character of his catastrophism is shown, however, by his skepticism about Élie de Beaumont’s theory of the parallel and paroxysmal elevation of mountain ranges: here he not only criticized the hasty generalization of the theory and its inapplicability to British geology but also emphasized the slow and gradual nature of many—though not all—tectonic movements (8). His presidency of the Geology Section of the British Association in 1832 gave him an opportunity to review the general progress of the science (9). Here, and later in an important letter to Lyell (10), he expounded his own theoretical viewpoint. This combined an actualistic method in geology with an acceptance of occasional paroxysmal episodes, the overall trend of earth history being one of progressive diminution in the intensity of geological processes coupled with a progressive rise in the complexity of the organic world, culminating in the appearance of man.

BIBLIOGRAPHY

Works are listed in the order cited in the text.

(1) Conybeare and W. Phillips, Outlines of the Geology of England and Wales, With an Introductory Compendium of the General Principles of That Science, and Comparative Views of the Structure of Foreign Countries. Part I [all issued] (London, 1822).

(2) W. Buckland and Conybeare, “Observations on the South Western Coal District of England,” in Transactions of the Geological Society of London, 2nd ser., 1 , pt. 1 (1822). 210–316.

(3) Conybeare, “Memoir Illustrative of a General Geological Map of the Principal Mountain Chains of Europe,” in Annals of Philosophy, n.s. 5 (1823), 1–16, 135–149, 210–218, 278–289, 356–359; n.s. 6 (1824), 214–219.

(4) Conybeare and H. T. De La Beche, “Notice of a Discovery of a New Fossil Animal, Forming a Link Between the lchthyosaurus and the Crocodile; Together With General Remarks on the Osteology of the Ichthyosaurus,” in Transactions of the Geological Society of London, 5 (1821), 558–594; Conybeare, “Additional Notices on the Fossil Genera Ichthyosaurus and Plesiosaurus,” ibid., 2nd ser., 1 pt. 1 (1822), 103–123; and “On the Discovery of an Almost Perfect Skeleton of the Plesiosaurus,” ibid., pt. 2 (1824), 381–389.

(5) Conybeare, “On the Hydrographical Basin of the Thames, With a View More Especially to Investigate the Causes Which Have Operated in the Formation of the Valleys of That River, and Its Tributary Streams,” in Proceedings of the Geological Society of London, 1 , no. 12 (1829), 145–149.

(6) Conybeare, “Answer to Dr Fleming’s View of the Evidence From the Animal Kingdom, as to the Former Temperature of the Northern Regions,” in Edinburgh New Philosophical Journal, 7 (1829), 142–152.

(7) Conybeare, “On Mr Lyell’s ‘Principles of Geology,’” in Philosophical Magazine and Annals, n.s. 8 (1830), 215–219; and “An Examination of Those Phaenomena of Geology, Which Seem to Bear Most Directly on Theoretical Speculations,” ibid., 359–362, 401–406; n.s. 9 (1831), 19–23, 111–117, 188–197, 258–270.

(8) Conybeare, “Inquiry How Far the Theory of M. Élie de Beaumont Concerning the Parallelism of the Lines of Elevation of the Same Geological Area, Is Agreeable to the Phaenomena as Exhibited in Great Britain,” in Philosophical Magazine and Journal of Science, 1 (1832), 118–126; 4 (1834), 404–414.

(9) Conybeare, “Report on the Progress, Actual State and Ulterior Prospects of Geological Science,” in Report of the British Association for the Advancement of Science, 1831–2 (1833), pp. 365–414.

10. M. J. S. Rudwick, “A Critique of Uniformitarian Geology: A Letter From W. D. Conybeare to Charles Lyell, 1841,” in Proceedings of the American Philosophical Society, 111 (1967), 272–287.

In addition, see F. J. North, “Dean Conybeare, Geologist,” in Transactions of the Cardiff Naturalists’ Society, 66 (1933), 15–68.

M. J. S. Rudwtck

Conybeare, William Daniel (1787–1857) An English clergyman, Conybeare is best known as co-author, with William Phillips, of Outline of the Geology of England and Wales (1822), one of the most influential textbooks on stratigraphy of the period. He also described and reconstructed saurian fossils from the Lyme Regis area of England. As a friend and collaborator of William Buckland, Conybeare was an influential member of the Oxford School of Geology.