TOEHBNTS OF THE HIGH ALPS. 



41 



can give us an idea, the waters have necessarily found in this chaos the 

 matter of these enormous alluvial deposits. The rivers were acting at that 

 time as our torrents do now — -that is as these torrents do which have for 

 their basins of reception entire chains of mountains, and which precipitate 

 themselves across a soil newly disturbed and susceptible of being washed 

 away, quite otherwise than that of our Alpine hUls. Many hypotheses have 

 been proposed to explain the origin of the Alpine pudding-like deposits. 

 Along the Durance banks of these are met with which rise to upwards of 

 100 metres, or 330 feet, above the actual level of the waters. But the 

 dejections of extinct torrents are, relatively to the trifling streamlets which 

 now furrow them, deposits still more surprising, and of an appearance more 

 inexplicable ; we are, nevertheless, well assured that they are the work of 

 these streamlets in the first period of their action. Why then may it not 

 be the same in regard to the puddings being the work of rivers in a period 

 in every respect similar ? 



" I point out these things in passing, not daring to stop to develope and 

 to follow out the views they suggest. This would take me too far away 

 from my subject. Everyone can understand that a mass of water roUing 

 over the soil must act in the same way and conform to the same laws, 

 whether it form a torrent or constitute a great river. Now, as we see formed 

 before our eyes the bed of torrents, we may infer that the bed ef rivers has 

 been created in the same manner. And this presumption is accordingly 

 confirmed by the study of such rivers as show traces of their action in bye- 

 gone times in the soil of the valley they have formed." 



In more than one of the British Colonies, and in other newly settled 

 lands — using that phrase as applicable to the immigration and settlement 

 of more highly-civUized nations than the native tribes — and in lands which 

 have not been so colonized, are rivers in some of the earlier forms of 

 development referred to. Now, dry channels, or channels threaded by a 

 tiny stream, and now filled from bank to bank — a mighty rushing flood — 

 carrying all before it, undermining banks and washing away the debris, the 

 analogues of the torrents studied by M. Surell, having like them their hasdn 

 de reception — one of immense extent — covering it may be thousands of 

 square miles, and embracing numerous secondary basins drained by affluents, 

 a thunder-shower falling in any one of which may produce a torrential 

 flood, — having their canal d'ecoulement, their water-course through which the 

 waters roU their flood along towards the sea, and their lit de dejection, or bed 

 of deposit, though this it may be is in the ocean-bed near tp, or remote from, 

 the shore, contributing in the former case to augment the bar which bars 

 the river's mouth. And it may be inferred that the application of like ' 

 remedies may produce Uke effects. What bridles the torrent like a young 

 lion in its fury may bridle the torrential river subject only occasionally to 

 fits of rage. 



Section III. — Remedial Appliances to prevent the Destructive Consequences 



of Torrents. 



The natural history of torrents is suggestive of a most efficient remedy, 

 but it is only of late years that it has been applied, and for its adoption we 

 are indebted greatly to the study of these torrents by Surell, though he was 



