SCENERY OF SWITZERLAND. 
253 
CHAPTER X. 
ON THE INFLUENCE OF THE STRATA UPON SCENERY. 
The character of Swiss scenery depends mainly 
on denudation and weathering, modified by the 
climate, the character, the chemical nature, the 
height, and the angle of inclination, of the rocks. 
The total thickness of the sedimentary rocks has 
been estimated roughly at 200,000* feet, and as the 
whole of this was deposited in seas or lakes and was 
derived from former continents, we see how enormous 
the amount of denudation must have been, especially 
if we bear in mind that much of it has been washed 
down and deposited, then raised and afterwards 
washed down again; some of it moreover several 
times. 
The principal forces which have disintegrated 
rocks are — (1) Water; (2) Changes of temperature; 
(3) Chemical actions; (4) Vegetation. 
There are few rocks which are not more or less 
alterable by, or soluble in, water. It soaks in and 
* Many of the beds, however, are not represented in Switzer- 
land. 
