CHAPTER XXIV, 



On the relative antiquity of different mountain-chains Theory of M. Elia de 

 Beaumont His opinions controverted His method of proving that different 

 chains were raised at distinct periods His proof that others were contempo- 

 raneous His reasoning, why not conclusive His doctrine of the parallelism 

 of contemporaneous lines of elevation Objections Theory of parallelism at 

 variance with geological phenomena as exhibited in Great Britain Objections 

 of Mr. Conybeare How far anticlinal lines formed at the same period are 

 parallel Difficulties in the way of determining the relative age of mountains. 



RELATIVE ANTIQUITY OF MOUNTAIN-CHAINS. 



THAT the different parts of our continents have been elevated, 

 in succession, to their present height above the level of the sea, 

 is an opinion which has been gradually gaining ground with 

 the progress of science ; but no one before M. Elie de Beau- 

 mont had the merit even of attempting to collect together the 

 recorded facts which bear on this subject, and to reduce them 

 to one systematic whole. The above-mentioned geologist was 

 eminently qualified for the task, as one who had laboured 

 industriously in the field of original observation, and who 

 combined a considerable knowledge of facts with an ardent 

 love of generalization. 



But he has been ambitious, we think unfortunately, of 

 anticipating the march of discovery in reference to the compa- 

 rative antiquity of different mountain-chains and their sup- 

 posed connexion with changes in the animate world. His 

 speculations differ entirely from the conclusions to which we 

 have arrived, and we therefore think it necessary to explain 

 fully the reasons of our dissent. In order to put the reader in 

 possession of the principal points of M. de Beaumont's theory, 

 we shall first offer a brief sketch of them, and then proceed 

 to analyze the data on which they are founded. 



VOL. Ill, Z 



