GANGES. 219 



glass of water," he says, " taken out of this river when at 

 its height, yields about one part in four of mud. No won- 

 der, then, that the subsiding waters should quickly form a 

 stratum of earth, or that the delta should encroach on the 

 sea." Rennell also computed the mean quantity of water 

 discharged into the sea by the Ganges through the whole 

 year to be 80,000 cubic feet in a second. When the river 

 is most swollen, and its velocity much accelerated, the 

 quantity is 405,000 cubic feet in a second. Other writers 

 agree that the violence of the tropical rains, and the fine- 

 ness of the alluvial particles in the plains of Bengal, cause 

 the waters of the Ganges to be charged with foreign matter 

 to an extent wholly unequalled by any large European 

 liver during the greatest Hoods. The Ganges frequently, 

 sweeps down large islands, and Colebrooke relates exam- 

 ples of the rapid filling up of some branches of this river, 

 and the excavation of new channels, where the number of. 

 square miles of soil removed in a short time was truly 

 astonishing, the column of earth being 114 feet high. 

 Forty square miles, or 25,600 acres, are mentioned as hav- 

 ing been carried away in one district in the course of a few" 

 years. If we compare the proportion of mud, as given by 

 Rennell, with his computation of the quantity of water 

 discharged, very striking results are obtained. If it were- 

 true that the Ganges in the flood season contained one part 

 in four of mud, we should then be obliged to suppose that 

 there passes down every four days a quantity of mud equal 

 in volume to the water which is discharged in the course of 

 twenty-four hours. If the mud be assumed to be equal to- 

 one-half of the specific gravity of granite (it would, however,. 

 be more), the weight of matter daily carried down in the flood 

 seasons would be equal to seventy-four times the weight o£^ 

 the Great Pyramid of Egypt. Even if it should be proved 

 that the turbid waters of the Ganges contain one part itiv 

 100 of mud, which is affirmed to be the case in regard to 

 the Rhine, we should be brought to the extraordinary con- 

 clusion, that there passes down every two days into the Bay 

 of Bengal a mass about equal in weight and bulk to the 

 Great Pyramid. 



The following table is given by Hamilton of the probable 

 length of some of the rivers of India : — 



