480 THE FORMATION OF RIVER GORGES. 



remains, in the form of a canon, as a testimony to the 

 ages of persistent work by which this has been effected ; 

 if on the other hand it was through softer strata, such 

 as gravel or clay, slides have occurred, and masses ot 

 fallen stuff have been precipitated into the river. This 

 material the giant labourer makes short work of, and 

 quickly shovels it away, and removes it in the form 

 of sand, gravel, or mud, which it spreads over the first 

 convenient lowlands beneath. It is in this way that 

 many alluvial flats are formed. The gorge will thus 

 gradually have assumed the form of a valley with 

 sloping sides, through which the river flows. In the 

 Upper Mississippi and other great rivers, such a valley 

 will sometimes be several miles in width to the bluffs 

 which enclose it, through the channel having changed 

 its course from time to time. 



The carrying power of water is as we know enormous. 

 In our preceding section we gave some details concern- 

 ing the immense blocks of granite, some of them fully 

 ten feet in diameter, that have been carried down for 

 many miles by the torrent known as the great Rangit, 

 which flows through the gorges of the Himalaya 

 Mountains of Sikkim, and bursts its way into the Indian 

 plains by the valley that leads down from the Darjeeling 

 plateau. 



We must not lose sight of the fact that the weight 

 of every gallon of standing water is 8 Ibs. : consequently 

 when a heavy fluid of this density is confined within 

 narrow boundaries by enclosing walls of rock, and the 

 current is propelled by gravitation down a steep incline, 

 there is literally no limit to what water may not be 

 capable of doing. 



A wonderful example of such a torrent can be seen 



