C.—GEOLOGY. 63 
in the nineteenth century and the discovery of the geographical outlines 
of the hitherto unknown regions, the efforts to correlate the main 
structures in the relief of the earth were resumed. The most stimulating 
worker in this field was then Elie de Beaumont. His correlation and 
classification of mountain chains were based on the view that the interior 
of the earth is slowly cooling and contracting so that the rigid outer shell 
undergoes alternate deformation and recovery of the spheroidal form 
when the crust again closely embraces the shrinking internal mass. Elie 
de Beaumont concluded that these crustal movements account for the 
mountain ranges and main relief of the earth. He realised that the crust 
is a unit which is affected as a whole by each of the orogenic episodes which 
upheaved mountain systems at the same date in even distant parts of 
the earth. He regarded these episodes as separated by long intervals of 
repose, and held that fold-mountain chains of the same orogeny are 
recognisable by their trend. He classified the mountains of Europe into 
four systems, upraised at different dates and each with a characteristic 
trend, and he claimed that all the members of each system are parallel, 
according to his use of that term. As the trends were determined by the 
fracture of a spherical or subspherical shell, he considered that they 
would be on a regular geometrical pattern, liable to merely local variations, 
for he treated the crust as practically uniform in strength. 
Elie de Beaumont’s views attracted earnest attention and at the first 
meeting of the Association Sedgwick and Conybeare were asked to report 
whether his maxim that mountain ranges with the same trend were of the 
same age holds true for the British Isles. The two authors” issued a 
brief report. Sedgwick declared that the older British strata are in strict 
accordance with Elie de Beaumont’s theory (ibid., p. 591) and expressed 
enthusiastic approval of it in his Presidential Address to the Geological 
Society. ‘The steps,’ said Sedgwick,” ‘by which he reaches this noble 
generalisation are so clear and convincing as to be little short of physical 
demonstration. It forms an epoch in the history of our science; and I 
am using no terms of exaggeration when I say, that in reading the 
admirable researches of M. de Beaumont, I appeared to myself, page 
after page, to be acquiring a new geological sense, and a new faculty of 
induction ; and I cannot express my feelings of regret, that during my 
recent visit to the Eastern Alps I did not possess this grand key to the 
mysteries of nature.’ 
Elie de Beaumont’s system appeared to be opposed in one respect 
to Lyell’s; for whereas it laid stress on violent earth-movements at 
recurrent episodes, Lyell laid stress on the continuity of geological evolu- 
tion, and held that the changes in progress to-day have never been inter- 
rupted by different forces or by the same forces acting with extraordinary 
energy. Sedgwick declared the opposition of the two systems and his 
adherence to that of Elie de Beaumont (ibid., p. 311). He said ‘that 
the system of M. Elie de Beaumont is directly opposed to a fundamental 
principle vindicated by Mr. Lyell, cannot admit of doubt. And I have 
decided to the best of my judgment, in favour of the former author, 
2 Rep. B.A. 1st and 2nd meetings, 1831-1832, pp, 587-91. 
28 Proc. Geol. Soc., vol. I, 1832, p. 308. 
