60 Lincolnshire Notes & Queries. 



of flood. The Triassic and Rhoetic escarpment, which now 

 bounds it on the east, is a very weak one at the best ; and 

 only here and there, in places like Gate Burton, Gainsborough, 

 and Burton Stather, does it present anything like a formidable 

 barrier ; while, in many parts, it is a mere bank, and scarcely 

 that ; but', as years went on, and its new channel through the 

 soft Keuper marls was deepened, this tendency would gradually 

 diminish. 



The Trent has always been liable to floods. Before its 

 course was changed the narrowness of the Lincoln outlet 

 prevented any rush of water getting away quickly ; and the 

 wide extent of ground covered by gravel deposits between 

 Newark and Lincoln shows how greatly the land around was 

 flooded. 



At that distant period, also, a powerful tributary, which has 

 left its mark on the land in the shape of an ancient gravel-bed, 

 entered the Trent near Lincoln, adding to the difficulty. 



This stream, according to Mr. Jukes-Browne, had its source 

 among the hills near Belvoir Castle, where the small river 

 Devon, its modern representative, now rises. 



Other similar streams would doubtless drain into the river 

 from the "longitudinal" valleys on either side, making matters 

 worse, so that, in time of flood, the entire area west of Lincoln 

 would often, for weeks together, be a sea of water. The river 

 Witham, however, at this period followed a course of its own. 

 Instead of running into Brayford, at the foot of the Oolite 

 escarpment at Lincoln, as it now does, it passed, as a "transverse" 

 stream, through that escarpment at Ancaster, and flowed thence 

 into the Wash. How it came to take its present course is not 

 exactly known. It was certainly after the Trent had been 

 captured by the Humber, and it may have been due to the 

 wearing back of the " longitudinal " valley in which it now 

 runs ; but, as there are signs of the uplifting of the land in the 

 neighbourhood of the Ancaster gap, through which it formerly 

 flowed, it may, in this way, have been turned aside and forced 

 into its present channel. Prof. Davis thinks its course was 

 changed by capture, and says " One of the greatest successes 

 of the Trent was the capture of the upper Witham, as 

 explained by Mr. Jukes-Browne." As a fa el, however, the 

 latter leaves the question open, and I am inclined to think, 

 indeed I see no reason to doubt, that the channel was turned 

 by the elevation of the land at Ancaster, where there has been 

 a distinct uplifting of the strata. 



