CHAPTER XXIV. 
On the relative antiquity of different mountain-chains — Theory of M. Elie 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. III. ' z 
