294- On the relative Age of the 



undergone, at distant periods separated l)y inter valb of tranquil- 

 lity. . 



Perhaps on a future occasion, I shall present a brief sketch of 

 these great phenomena ; but in the present article, I shall con- 

 fine myself to a single subject, the relative age of the different 

 mountain chains in Europe. In selecting this subject, T have 

 been less determined by its novelty, than by the clearness and 

 methodical accuracy with which M. Elie de Beaumont has treat- 

 ed it. I have also to say, that I have had the advantage of de- 

 riving from his friendly communications information without 

 which it would have been impossible for me to draw up the pre- 

 sent article, the original memoir not having yet made its ap- 

 pearance. It does not belong to me to foresee the estimation in 

 which geologists will hold M. Elie de Bcaumont^s investiga- 

 tion ; but I am greatly deceived if they will, not unanimously 

 consider it as one of the most curious and best conducted. The 

 very favourable rejx)rt which MM. Brongniart, Brochant, and 

 Bcudant iiave given of it in the Academy of Sciences, will, 

 I suppose, ensure for it the approbation of all the scientific 

 world. 



It is an opinion now nearly universally admitted, that the 

 mountains have been formed by upraising; that they have issued 

 from the bowels of the earth by violently jjerforating its crust, 

 so that there has perhaps been a period when the surface of the 

 globe presented no remarkable inequalities. 



Since this view has been adopted, difficulties that have hitherto 

 proved insuperable have disappeaicd from science. It will be 

 seen for example, how we can now explain the presence of shells 

 on the summits of the loftiest mountains, without supposing that 

 the sea had covered them in their present state. It is sufficient 

 to say, in fact, that these mountains, in issuing from the bosom 

 of the waters, raised with them, and carried to a height of three 

 or four thousand yards, the formations deposited by the sea. 



The moment the geologist admits the formation of mountains 

 by means of upraising, numerous interesting subjects of inquiry 

 present themselves to him He has to ask, for example, if all 

 the great chains have risen at the same period ; and in the case 

 of a negative reply, what is the order of their relative antiquity. 



