LOGIN NORTH-INDIAN GEOLOGICAL CHANGES. 197 



scooped out"^. So also it would be premature to attempt to fix any 

 date for the upheaval of the Sewaliks, and much more so to say when 

 Delhi formed the most northern point of a large island, if ever the 

 sea did reach north of where Delhi now is. 



In fact this may be questioned, owing to the similarity of the soil 

 and boulders brought up for the last 15 feet or so of the boring to 

 that of the boulders and clay just below Kalka, where the Umballa 

 and Kalka road crosses the line of the Sewaliks, which are very low 

 at this point ; and it was in the Sewalik range that Ealconer and 

 Cautley made their discoveries. If the strata immediately below 

 the point now reached at UmbaUa are identical with the upper 

 strata of the Sewaliks, fossil remains may be found ; but up to the 

 present time there have been no signs of animal or vegetable lifef. 



Should the strata be the same, we have now reached, at 450 feet 

 above the sea at Umballa, strata which at 30 miles north of it are 

 over 2000 feet above the sea ; and if this curvilinear theory is correct, 

 they were here deposited at a depth of about 1000 feet below their 

 present level. 



This will give a fall of over 15 feet a mile, or quite enough to 

 roll along (in a moderately deep torrent) small boulders such as 

 those met with near Umballa at 450 feet below the surface. If 

 therefore large animals lived when the plains at Umballa were only 

 half their present height above the sea, this might lead one to sup- 

 pose that the sea did not reach as far north as Delhi, and possibly 

 never did during the period now treated of. 



This, however, is not the object of the paper to prove ; but what it 

 is wished to show is, that the plains of India were formed by moun- 

 tain-streams in a similar manner to what we see at the present day — 

 that though the deposits are irregular transversely, yet longitudinally 

 the section is uniform, probably forming a regular curve. This 

 curve Mr. Tylor proves to approximate to a true parabola in certain 

 cases ; and what I have observed of the torrents out here in India, 

 and a few small experiments I have made, all go to support this view. 

 To the geologist this would be a very interesting point to determine ; 

 but to the Hydraulic Engineer it is most important, as it would at 

 once show that there is some relation between the load of solid matter 

 flowing water can hold in suspension and the slope of the ground the 

 water flows over — as,for example, that we cannot suddenly change the 

 slope of an artificial river or canal without also modifying the load 

 of solid matter to be carried. The second point of importance is the 

 fact that the boring shows that we have heavy matter deposited 

 over lighter matter, sand over soft clay, small stones over sand. 

 This is also shown by the deposits in the Markunda (p. 190), 

 where these were : — fii'st, dirty fine sand; next, soft clay, and over this 



* My estimate of the rise of the head of the delta of the Irrawaddy was 

 1 iBch in 30 years. See ' Proceedings of the Royal Society of Edinburgh ' for 

 March 1857. 



t Only on one occasion, at about 440 feet below the surface, were a few pump- 

 fulls of a blackish putrid water brought up, giving off very much the same 

 odour as the dirty bilge-water of a ship. 



VOL. XXVIII. PART I. P 



