352 DISTRIBUTION OF BOULDER STONES. 



If, during a flood, a rupture takes place in the banks 

 of a river, where it is contracted, a part of the stream 

 will flow out by the lateral opening, and carry along with 

 it rolled masses, even when the opening in the bank does 

 not reach to the bottom of the bed of the river ; for the 

 mountain stream, loaded with boulders, carries them not 

 merely in single masses along its bottom, but the flood- 

 water of the stream generally attacks large sandbanks, 

 or older beds of rolled masses, and carries along with it, 

 accompanied with a terrible noise, whole masses, forces 

 them over the lower banks, or through the chasm in the 

 bank, and often deposites them several feet high, on an 

 immediately succeeding widening of the river's course. 



In the same manner, we observe loose blocks deposit- 

 ed on high situations in the lateral valleys of the great 

 transverse valleys, and dispersed over the passes into the 

 neighbouring valleys. The height of the lateral depo- 

 sites of loose blocks, and their position in the passes, and 

 their passing into neighbouring valleys, are facts which 

 assist us in judging of the extent of the power that may 

 have acted during their transportation. 



The striking agreement observable in the phenomena 

 of the distribution of the loose blocks from the interior 

 Alpine valleys to the interior valleys of the Jura, with 

 those in the rolled masses carried along by rivers, must 

 lead every one, who reflects on this interesting pheno- 

 menon, to the hypothesis, that these blocks may have 

 been deposited in their present situations by an overwhelm- 

 ing flood, which burst from the Alps. It is true that this 

 opinion is liable to many objections ; but still it contains 

 a more plausible explanation of the phenomenon than 

 any other with which we are acquainted. 



