308 Geological Society. 



the ages of the inclined and horizontal strata be defined, we also 

 necessarily define the period of the elevation. 



This kind of reasoning has for some years been familiar to the 



feologists of Europe. Mr. Webster endeavoured to prove that the 

 sle of Wight had been upset after the period of the London clay, 

 and before that of the lacustrine rock marl. Every one now admits, 

 (and indeed it is made the foundation of one of the classifications 

 of Mr. Conybeare,) that our carboniferous chains were elevated 

 before the period of the new red sandstone. 



But the researches of M. Elie de Beaumont, to which I now wish 

 to direct your attention, have given a vast extension to the obser- 

 vations of all those who had gone before him. And before I pro- 

 ceed I cannot but lament that persons, who have not perhaps com- 

 prehended the meaning of this admirable observer, should have 

 nibbled at the originality of his discoveries ; as if the very essence 

 of philosophical discovery did not often consist in bringing to a 

 point all the scattered lights of former observations, and giving 

 generalization to insulated phenomena. 



In the first place then, by an incredible number of well conducted 

 observations of his own, combined with the best attested facts re- 

 corded by other observers, he has proved, on the principles already 

 pointed out that whole mountain chains have been elevated at one 

 geological period that great physical regions have partaken of the 

 same movement at the same time and that these paroxysms of 

 elevatory force have come into action at many successive periods. 

 Distinguished as are his merits, he so far claims not an undivided 

 honour. But in the next great step of generalization he reaches a 

 position where he stands entirely by himself. 



Step by step we had been advancing towards the conclusion 

 that different mountain chains had been elevated at several distinct 

 geological periods : and by a long series of independent observa- 

 tions, Humboldt, Von Buch, and other great physical geographers, 

 had proved that the mountain chains of Europe might be separated 

 into three or four distinct systems ; distinguished from each other, 

 if I may so express myself, by a particular physiognomy, and, above 

 all, by the different angles made by the bearings of their component 

 formations with any assumed meridian. All the subordinate parts 

 of any one system were shown to be parallel ; while the different sy- 

 stems were inclined at various angles to each other. 



By an unlooked-for and most felicitous generalization, M. Elie 

 de Beaumont has now proved that these two great classes of facts 

 are commensurate to each other; and that each of these great 

 systems of mountain chains, marked on the map of Europe by given 

 parallel lines of direction, has also a given period of elevation, limit- 

 ed and defined by direct geological observation. The steps by which 

 he reaches this noble generalization 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 exaggera- 

 tion 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 



