THE MOVING WATERS 



surface waters are constantly breaking up the world's 

 coastlines and carrying material away from the shores, 

 but the breakers and rollers are only responsible for a 

 part of the land material which the sea receives. It has 

 enormous power, infinite patience, and an insatiable 

 appetite — an appetite which is fed not only by its own 

 efforts, but by its numerous allies. Forever and forever, 

 growing in size and strength as they labour, the world's 

 streams and rivers carry sediment down to the sea, 

 robbing the land — sediment which the sea greedily 

 swallows, its monstrous appetite unappeased. 



The Mississippi alone carries down the Gulf, day by 

 day and every day, over a million tons of sediment. 

 Professor Salisbury, in his great work Physiography,'^ says : 

 "It would take nearly 900 daily trains of fifty cars each, 

 and each car carrying twenty-five tons, to carry an equal 

 amount of sand and mud to the Gulf All the rivers of the 

 earth are perhaps carrying to the sea forty times as much 

 as the Mississippi." This estimate gives us a mental picture 

 of sediment being carried into the oceans every day 

 amounting to over forty million tons. 



Professor Salisbury makes the significant statement 

 that "Every drop of water which falls on the land has for 

 its mission the getting of the land into the sea". He is 

 not exaggerating when he says that this is the main task 

 of the world's rivers. 



Perhaps the Yangtse Kiang and the Hwang Ho are 

 the two rivers which are the most active levellers of the 

 world's continents. The former carries to the sea three 

 times as much sediment as the Ganges. Fabre, in his 

 fascinating work This Earth of Ours,] estimates that the 

 matter carried into the sea by the Yangtse Kiang is 

 even greater than that carried into the sea by the Mis- 

 sissippi. He uses shiploads, instead of trainloads, to illus- 

 trate his statement: "For conveyance by vessel of this 



♦Murray, 1907, 

 fFisher Unwin, 1923. 



75 



