﻿Tlie Struchire of Europe. 243 



new complicated system of foldings, pressed in their turn 

 against those lying further north. 



It seems almost to be a law of nature that every new 

 series of foldings should be piled up from the south 

 against the older mountains, a phenomenon the recognition 

 of which belongs to most recent times. We can also 

 observe how these most recent foldings are to-day being 

 broken down, how on their inner edges here and there 

 masses of volcanic rock occur. 



It was formerly believed that the upheaval of mountains 

 was brought about by volcanic masses being forced up 

 from the depths, pushing before them the superincumbent 

 rocks. To-day we see, on the contrary, that molten 

 masses have passively appeared, where disturbances of the. 

 earth's surface have presented to them this possibility, 

 just as blood wells out of a wound. From these subsi- 

 dences we see that the whole inner concave side of the 

 youngest system is engaged in caving in. The west coast 

 of Italy exhibits a whole series of saucer-shaped depres- 

 sions, bounded each by two pillars which remain standing. 



The ground on which we stand here in Vienna is an 

 example of such a cave-in, and here this phenomenon was 

 first accurately studied. 



The outer margin of the Alps runs to Kahlenberg, 

 continues to Bisamberg and forms little solitary hills in 

 Nikolsburg, which forms the connection with the first 

 spurs of the Carpathians. 



Behind this a breach has been formed. On the further 

 side of this gap the inner zones of the Alps stretch from 

 the Kosalien mountains and Letha mountains to the 

 Hundsheim mountains and the Carpathians. Along the 

 faults hot springs arise : Baden, Voslau ; and on this 

 sunken portion lies Vienna. Thus was formed a portal 

 for the exit of the Danube; in this way the northern 

 slopes of the Alps were given the possibility of draining 

 to the southward. This way was traced out by nature, 



