450 E.. Suess— Origin of the Alps. 
exist in central Kurope. If we look at the subject more broadly, 
however, and pass out of Europe to America, and then further 
study in as great detail as is now possible the great mountain- 
chains of Asia, we arrive at this grand conclusion : throughout, 
mountain-masses and mountain-movements are one-sided, and 
the direction of the movement is in general northwest, north, 
or northeast, in North America and Europe, but southerly, or 
southeasterly, in central Asia. There is no regular geometrical 
arrangement in the mountain chains. 
Looking at the facts which have been stated, making only 
the supposition that an unequal contraction of the surface of 
the planet has taken place, we see that the simplest form of 
mountain consists in a fracture, which runs at right angles 
to the direction of the contraction ; the fractured part moves 
forward in the direction of the force from contraction, while 
volcanic phenomena may manifest themselves at the line of 
breakage. The Erzgebirge forms an example of such a moun- 
teep line, as a rule, on the inner side of the fracture, while the 
