CHAP. XXXIV.] OF DELTA OF MISSISSIPPI. 251 



amount of sediment would have been brought down 

 from the interior in a given time, and consequently 

 a deduction would have to be made from the number 

 of centuries above stated on that account. But, on 

 the other hand, if it could be shown, by more accurate 

 experiments and calculations, that the quantity of 

 water in the above computation was greatly defi 

 cient, say even one-third less than the real quantity, 

 I do not imagine that any exaggeration has been 

 made in the time supposed to have elapsed since the 

 rivers began to transport their earthy ingredients to 

 the alluvial plains of Louisiana. The delta is, after 

 all, a mere fragmentary portion of a larger body of 

 mud, the finer particles of which never settle down 

 near the mouths of the Mississippi, but are carried 

 far out into the Gulf, and there dispersed. 



The description which I have given of the great 

 distance to which the yellow and lighter streams of 



me by Messrs. Riddell, Forshey, and Carpenter, in the hands of 

 my friend, Mr. George Ronnie, F.R.S., to whom we are in 

 debted for many valuable papers on the application of the 

 science of hydraulics to rivers (see Report of British Asso 

 ciation, vol. iii. p. 415. 1834), and, after examining them, he 

 came to conclusions which did not vary materially from those 

 which I had previously announced. Mr. James Nicol, As 

 sistant Secretary of the Geological Society of London, before 

 he had seen Mr. Sidell s experiments, had expressed to me his 

 belief that the quantity of water carried to the Gulf by the 

 Mississippi, must be greater than I had assumed from Mr. 

 Forshey s calculations, judging from the amount usually as 

 signed as the annual discharge of rivers having hydrographical 

 basins smaller than that of the Mississippi. 



M G 



