238 GENERALIZATIONS. 



ther, that we do not know whence the enormous mass of water 

 which it requires could have come. It is far more likely that 

 the level of the sea was never much further from the centre of 

 the earth than it is at present, and that thus it represents a sur- 

 face stretched over the globe, to which the risings and sinkings 

 of the terrestrial crust can be referred. That such risings and 

 sinkings are constantly taking place is a fact ascertained by ob- 

 servation, and justifying the deduction of inferences as to former 

 conditions. In the present volume (p. 198) Prof. Heer has 

 noticed the rising of the Norwegian coast. The shores of 

 Devonshire have been upheaved in comparatively recent times ; 

 for near Torbay, considerably above the sea-level, a zone may 

 be seen containing animals all of which still live in the sea at 

 that place. A similar upheaval, but on a much greater scale, is 

 taking place on the coasts of Chili in South America, where 

 marine animals of the present epoch are found several hundred 

 feet above the level of the sea. 



These upheavals may extend uniformly over whole continents, 

 and are then called continental ; or they may affect only parti- 

 cular regions, or exert themselves only in particular directions, 

 when they are denominated partial. A close relation has ex- 

 isted between the upheavals and the depressions of the surface ; 

 and the lowering of the ground forms part of a general system, 

 as when whole continents sank down and sometimes were again 

 covered by the sea, or they are only partial, when limited to 

 particular regions of the land and inducing wide-spread sinkings 

 by falls in the interior of the earth. 



As to the causes of these upheavals and depressions, which have 

 been the chief agents in giving the crust of the earth its present 

 form, science has hitherto come to no conclusion. The hypo- 

 theses which have been invented to explain this grand natural 

 phenomenon are connected with opinions as to the formation 

 and earliest states of the earth; and the dispute is not yet 

 settled, which has been carried on for the last 2000 years, as to 

 whether fire or water has had most to do with the formation of 

 our planet. 



As the spherical form of the earth, its flattening at the poles, 

 and its bulging-out in the equatorial regions compel us to 

 assume that during its formation it has been in a fluid, or at 



