196 PEOCEEDi:XGS OF THE GEOLOGICAL SOCIETY. 



is upon this that the fertility of the country depends. Sand we do 

 find on the surface ; but this I attribute more to wind and want of 

 moisture than to aqueous action. Having thus got the surface in a 

 prepared state for man to inhabit and cultivate the soil, the up- 

 heaval took place, raising a barrier to the numerous streams which 

 then flowed over the plains, and only leaving openings or weak points 

 at intervals, as atHurdwar on the Ganges*, Tyzabad on the Jumna, 

 Rooper on the Sutledj, and so with the Punjab rivers. 



With the distance to the sea much shorter than at present, and 

 the volume of water probably much greater, this water, with only 

 a few channels to escape through at these gaps in the bills, must 

 have rushed down with great violence, cutting and tearing before 

 it deep channels through the plains, such as we now find the valleys 

 of our great rivers, which are known by the name of Khader, in con- 

 tradistinction to Ehangur, or high-level plains. With channels thus 

 scooped out there must have been a cutting back ; and the course of 

 such minor streams as fall into the main rivers Avould be acted on 

 similarly. Thus we find that this cutting back on the valleys of 

 the Solani to near the foot of the hills must liave been very great ; for 

 there the valley is even now 20 feet below the Bhangur, or high- 

 level plain, and was probably much lower, while in width it could 

 not have been less than two miles. When such was the state of 

 things the velocity of the water must have been sufficient to carry 

 large boulders from the foot of the hills to a considerable distance 

 down the main rivers ; and to me this explains why such boulders 

 were found at a depth of 40 feet in the valley of the Jumna, when 

 sinking the foundations of the Jumna railway bridge. If it is owing 

 to this that in the Jumna valley at this point, which is quite as far 

 from the hills as Umballa, large boulders were found at 835 feet 

 above the sea, while as low down as 450 feet above the sea, at 

 Umballa, only small stones were met with (the largest only mea- 

 suring 5 X Sj in.), what clearer proof than this is necessary that 

 the beds of our large rivers are now being silted up rather than 

 lowered ? 



This is a most important and satisfactory conclusion to the en- 

 gineer ; for here we have a deposit of some 40 feet of sand ; and as 

 the Delta f is rising also, every point between must be undergoing the 

 same process, though perhaps not observable in one or even in 

 several generations. To attempt to assign any specified time for 

 such changes as we have been discussing, even for this last of all 

 geological periods, would be in vain ; but it probably required thou- 

 sands of years to fill up the beds of these rivers after they were 



* The opening thi-ougli which the Ganges flows at Hurdwar is called 

 " Beemgodah." Beem is a demigod of the Hindoos, who is said by them to 

 have planted his foot at Hurdwar, and thus made a passage through the Sewaliks 

 foi* the Granges. 



t [The Delta only rises in proportion as the mouths extend out to sea. If they 

 did not extend and lengthen, the level of the Delta would fall as the mean level 

 of the continent, being constantly diminished by the annual denudation due to 

 the action of rain and rivers. — A. T.] 



