Natural History. 55 



there, however, it leaves its course and bends to the north, 

 skirting the low Triassic and Rhcetic escarpment on the west, 

 "as if it had not been able to cross that comparatively slight 

 obstruction"; then, continuing past Gainsborough, it flows on 

 northwards until it is lost in the Humber. 



Now that this northward bend of the Trent, after reaching 

 Newark, is of comparatively recent origin, and that it formerly 

 continued its north-easterly course, and flowed through the gap 

 at Lincoln, is capable of proof; and the credit of suggesting 

 this is due to Mr. Penning, of the Geological Survey, when he 

 was engaged, in 1878, in mapping the gravel beds round 

 Lincoln. 



And what are the proofs ? First, it is, as Mr. Jukes-Browne 

 says in his paper before referred to, "a significant fact that if 

 the general course of the Trent, south-west of Newark, be 

 prolonged to the north-east, it points to the great gap in the 

 Oolitic escarpment at Lincoln through which the river 

 Witham now flows " ; but it is more significant to find that, 

 all along this north-east track, lie vast beds of ancient gravel 

 deposits, showing clear traces of river action, distinct from the 

 other and more modern gravels around (which latter, as I shall 

 show later on, are the result of floods to which the Trent has 

 always been greatly liable) ; and still more significant is the 

 fact that these ancient gravel beds carry with them incontestable 

 proofs of their origin, being " largely made up of rounded 

 pebbles of quartzite, hornstone, and other old rocks, which 

 have evidently been derived from the triassic pebble-beds 

 beyond Newark on the west " ; and as these ancient gravels, 

 with their component pebbles, are found in large quantities, 

 not only between Newark and Lincoln to the west of the gap, 

 but right through and far beyond it, on the east, they could 

 have been brought there only by the Trent, otherwise there is 

 no way of accounting for them. 



All this is, I submit, sufficient to convince any reasonable 

 mind that the present course of the river Trent is not its 

 original one, but that, ages ago, in early pre-glacial times (as 

 I think), and not post-glacial, as Mr. Jukes-Browne suggests 

 it passed through the Lincoln Gap to the fen-land beyond, 

 which was then probably an open bay. 



My reason for putting the date back to pre-glacial times is 

 that the submergence of the land in the eastern part of 

 England, during that age, was not sufficient to wear away its 

 then existing contour to any great extent ; and the denudation 



