Economic Geology. 27 



as well as those of success, since if we are to accept the 

 authority of a writer in the second vol. of the Transactions of 

 the institution of Civil Engineers, these would have led to 

 some modification of our present views on the subject, and 

 would certainly have tended to lessen our confidence in 

 the system generally. The tertiary basin of Paris has 

 also, as might be anticipated from its constitution, been 

 found admirably adapted for boring operations, and in it 

 they have been carried to the enormous depth of 1800 feet 

 (English). If we are to judge by the unfortunate issue of 

 the many attempts which have been made to obtain Arte- 

 sian springs in the delta of the Ganges, we would conclude 

 that such formations are not adapted for boring, and it may 

 be useful to consider briefly in how far this conclusion is 

 supported by the geological information furnished by the 

 most recent and most successful of the series. 



Had the delta of the Ganges been formed slowly and 

 gradually by sedimentary deposits from the river, without 

 the interference of disturbing forces, the inclination of the 

 strata composing it would have been so slight that the water 

 percolating them would have no tendency to rise above the 

 surface, and the establishment of overflowing wells would 

 consequently have been hopeless. The deepest section of 

 the delta we have as yet obtained shews however very clear- 

 ly that this uniformity has by no means prevailed uninter- 

 ruptedly during its formation, but that disturbing forces of 

 considerable, occasionally of great, intensity have at different 

 periods been in active operation, altering the relative level of 

 the country over which the river has flowed, and producing 

 changes in the bed of the receiving basin itself. The nature 

 of the fossil remains, and the dimensions of the gravel found 

 at 480 feet from the surface of the ground, the greatest 

 depth hitherto attained, were such as to lead Dr. M'Clelland 

 to the conclusion, that when these were originally deposited 

 bold rocky mountains existed in close proximity to the pre- 



