3IO DATA AND CONCLUSIONS. [chap. xiv. 



Europe : — then would the land from the North Sea to 

 the Mediterranean have been violently shaken, and at 

 the same instant of time a large tract of the eastern coast 

 of England would have been permanently elevated, 

 together with some outlying islands — a train of volcanoes 

 on the coast of Holland would have burst forth in action, 

 and an eruption taken place at the bottom of the sea, 

 near the northern extremity of Ireland — and lastly, the 

 ancient vents of Auvergne, Cantal, and Mont d'Or would 

 each have sent up to the sky a dark column of smoke, and 

 have long remained in fierce action. Two years and three- 

 quarters afterwards, France, from its centre to the English 

 Channel, would have been again desolated by an earthquake, 

 and an island permanently upraised in the Mediterranean. 



The space, from under which volcanic matter on the 20th 

 was actually erupted, is 720 miles in one line, and 400 miles 

 in another line at right angles to the first : hence, in all 

 probability, a subterranean lake of lava is here stretched 

 out, of nearly double the area of the Black Sea. From the 

 intimate and complicated manner in which the elevatory and 

 eruptive forces were shown to be connected during this train 

 of phenomena, we may confidently come to the conclusion, 

 that the forces which slowly and by little starts uplift con- 

 tinents, and those which at successive periods pour forth 

 volcanic matter from open orifices, are identical. From 

 many reasons, I believe that the frequent quakings of the 

 earth on this line of coast are caused by the rending of 

 the strata, necessarily consequent on the tension of the 

 land when upraised, and their injection by fluidified rock. 

 This rending and injection would, if repeated often enough 

 (and we know that earthquakes repeatedly afi'ect the same 

 areas in the same manner), form a chain of hills ; and the 

 linear island of St. Mary, which was upraised thrice the 

 height of the neighbouring country, seems to be under- 

 going this process. I believe that the solid axis of a 

 mountain, difi'ers in its manner of formation from a 

 volcanic hill, only in the molten stone having been re- 

 peatedly injected, instead of having been repeatedly ejected. 

 Moreover, I believe that it is impossible to explain the 

 structure of great mountain-chains, such as that of the 

 Cordillera, where the strata, capping the injected axis of 

 plutonic rock, have been thrown on their edges along 

 several parallel and neighbouring lines of elevation, except 

 on this view of the rock of the axis having been repeatedly 



