234 Journal of the Asiatic Society of Bengal. {| November, 1905. 
the river from one bank would be increased, while the slope to the 
other bank would be decreased. Consequently, denudation on one 
side of the river would be greater than on the other. The same 
thing would happen to all the rivers flowing on parallel courses. 
Thus, in the area between two rivers which run on nearly parallel 
courses, the denudation into one river would be greater than into 
the other. Each river would, in time, force the water-shed on one 
bank back towards the next river, but, in exchange, would lose on 
the other bank an equivalent in its catchment area. 
The result would be that each river would have a larger 
catchment area on one bank thanon the other. This appears to 
be the case in several districts of the United Provinces with which 
I was acquainted. 
Canals are generally aligned to run along the water-sheds, 
and in the following cases the canals are aligned very near the 
rivers running parallel to them on the north side :— 
(a) The main upper Ganges canal in the Aligarh District is 
very much nearer the Kali Naddi on its north than 
the Jumna on the south. 
(6) The Anupshahr branch of the Ganges canal in the 
Aligarh District is very much nearer the Ganges on 
its north than the Kali Naddi on its south. 
(c) The projected Sarda canal in the Lucknow District was 
aligned very much nearer the Gumti on its north 
than the Sai on its south. 
The fact that, at Lucknow, water from a great depth rose to 
above the surface, shows not only that the strata at great depths 
are inchned, but that they are continuous over very considerable 
distances. 
This is a very interesting fact, because it has been conclu- 
sively shown that the surface strata are not continuous. 
For certain reasons too technical to be given here a good 
irrigation well can only be made where the masonry cylinder can be 
taken down to a firm clay stratum underlaid by waterbearing sand. 
A good deal of attention has therefore been paid to the strata 
near the surface, by which I mean down to a depth of say 125 
feet. 
Colonel Clibborn was deputed in the seventies to make an 
examination into the subject of wells, and, in his report published 
by the Board of Revenue of the North-West Provinces and Oudh, 
in a collection of papers relating to the construction of wells, it is 
clearly demonstrated that the clay strata so essential to the 
success of wells are not continuous. 
I might add that anyone practically acquainted with the 
construction of irrigation wells knows that Colonel Clibborn’s 
conclusions are correct. 
A very difficult problem is here presented to us ; how can 
we account for the fact that the surface strata are clearly not con- 
tinuous, while those at great depths appear to be continuous? Two 
possible explanations suggest themselves ; the firstis that at great 
