I 4 8 LEISURE-TIME STUDIES. 



past, just as the shells of modern foraminifera fall to the 

 bottom of existing oceans to form a chalky layer which may 

 be destined, when elevated, to form the chalk of the future. 

 Elevation of the earth's surface, thus exists as a primary fact 

 of geological science. But it may be conclusively shown 

 that, whilst at the present day certain areas of our earth's 

 surface are undergoing this process of upheaval, other areas 

 as surely exhibit an opposite or subsiding tendency. The 

 fact that land subsides must, however, be regarded in the 

 light of the obvious relations which exist between the sea 

 and the land. The subsidence of land is ascertained and 

 calculated by its fluctuations as regards the sea-level. Hence 

 it is necessary that the burden of the change should be laid 

 upon the shoulders of the land, and that the sea should be 

 shown to be a factor of constant and unvarying nature in 

 this process. That the water of the ocean obeys the same 

 laws as the fluid in a vessel, is a stable fact. Practically, we 

 may regard the sea-level as invariable ; and although theories 

 of the influence of a polar ice-cap as tending to disturb the 

 oceanic equilibrium are not wanting, such widely operating 

 causes, even if proved to exist, would affect areas of so 

 wide an extent that their influence would be of the most 

 slight and meagre kind. On the contrary, where the changes 

 between the level of land and sea are of a markedly local 

 description and limited to a certain defined area, the altera- 

 tion is clearly seen to have its seat in the land and not in 

 the sea, the level of which, outside the defined area of 

 change, can be shown to be absolutely unaltered. For 

 example, on the coasts of Devon and Cornwall the remains 

 of submerged forests are met with, the roots of the trees 

 being still fixed in the soil. As these trees must have grown 

 on land, it follows that the incident reveals the submergence 

 of a land-surface. If we credit the sea with having risen, 

 and suppose that the land has been stationary, we must be 

 able to show not only that the whole southern coast of 

 England has been similarly invaded by the sea, but that the 

 opposite coasts of France, and all the coasts bordering the 



