220 THE BEAUTIES OF NATURE CHAP, vi 



In the Alps the contortions are much 

 greater than in the Jura. Fig. 19 shows a 

 section after Heim, from the Spitzen across 

 the Brunnialp, and the Maderanerthal. It 

 is obvious that the valleys are due mainly to 

 erosion, that the Maderaner valley has been 

 cut out of the crystalline rocks s, and was 

 once covered by the Jurassic strata j, which 

 must have formerly passed in a great arch 

 over what is now the valley. 



However improbable it may seem that so 

 great an amount of rock should have dis- 

 appeared, evidence is conclusive. Ramsay has 

 shown that in some parts of Wales not less 

 than 29,000 feet have been removed, while 

 there is strong reason for the belief that in 

 Switzerland an amount has been carried away 

 equal to the present height of the mountains ; 

 though of course it does not follow that the 

 Alps were once twice as high as they are at 

 present, because elevation and erosion must 

 have gone on contemporaneously. 



It has been calculated that the strata 

 between Bale and the St. Gotthard have 

 been compressed from 202 miles to 130 



