Principles of Geology, 21 



think that little is wanting to complete the evidence of this portion of 

 the physical chronology of the earth. 



Werner, and most of the moderns, consider the phenomena which 

 have been unfolded by geological research, as the effects of causes 

 no longer in action. But Dr. Hutton believed that all the revolutions 

 which have visited the earth, were but the result of the ordinary op- 

 erations of nature, continued through very long periods of time. He 

 was of opinion that what is now sea, was formerly dry land ; and that 

 by the action of rains and rivers, materials are accumulated on the 

 bed of the sea, to produce the strata of new continents, which by 

 some convulsion, like many that have happened before, will be up- 

 lifted and laid bare, whilst that part of the earth which we inhabit, 

 will be sunk under the new ocean.* To this hypothesis it may be 

 objected, that it ascribes to the ordinary agents of nature, effects 

 which appear much beyond their power. General changes in the 

 relative situation of sea and land have been often supposed, but never 

 established by evidence j for Cuvier's conclusions drawn from the 

 alternations of marine and fresh water formations, apply only to lim- 

 ited districts 5 and since well-conducted inquiries into the natural his- 

 tory of antediluvian quadrupeds, have shewn satisfactorily that they 

 lived before the flood over a very large portion of the present con- 

 tinents, we have proof that at the period of the deluge, the sea and 

 land did not change their relative situations. 



The natural agents now employed in altering the face of the globe, 

 are fire and water. The former forces fluid matter from the interior, 

 and spreads it around the volcanic mountains 5 the latter is incessant- 

 ly occupied in lowering heights, wasting and smoothing precipices, 

 filling up vallies, and equalizing the surface. 



Action of the sea and tide rivers. — The records of his- 

 tory declare what large tracts of inhabited country have been lost in 

 - the sea, and what extensive surfaces of new land have arisen to con- 

 tract the dominion of water. Observation shews on our own shores 

 much of the reciprocal process of demolition and augmentation ; and 

 thus we are enabled to form a correct estimate of the effects of this 

 " war of sea and land."f Every sea-coast, and especially eveYj 

 great estuary, furnishes examples for contemplation ; and these ef- 

 fects are so similar in all parts of the world, that the mode of ex- 



t Hutton. 



• Eluvie mons est deductus in aequor. 



OVID, METAM. 



