EXCAVATIONS AT DEWLISH. 213 



a number show this unusual gloss, that it is a character to 

 be explained. It corresponds closely with the gloss seen on 

 stones polished by drifting sand, from the Egyptian desert ; 

 but a consideration of all the surroundings leads us to think 

 that it was probably produced by the action of water rather 

 than of wind. 



These polished flints are found in several isolated pipes 

 or pot-holes descending deep into the chalk, and quite out 

 of reach of any wind-eddies ; they are not confined to the 

 comparatively shallow trench examined in former years. 

 The sides of these pot-holes are curiously rounded and 

 smoothed, as though by swirling water ; they are not coated 

 with a film of black or red clay, as is usual in pipes formed 

 by the action of percolating rain-water. At one spot only 

 in the easternmost of the large pot-holes was seen a small 

 patch of the characteristic black clay lining ; showing 

 probably that this pot-hole, at any rate, had begun as a pipe. 

 At every point except this one patch the characteristic black 

 clay had been scoured aw T ay, and the clean washed sandy 

 gravel was directly in contact with the chalk. The small 

 pipe immediately beyond shows the ordinary black clay 

 lining. 



How did these curious pot-holes originate and what is 

 the meaning of their very unusual infilling ? We are 

 evidently dealing with an exceptional deposit formed under 

 unusual conditions, not with either an ordinary river deposit, 

 or with the infilling of a pipe in the chalk. At Dewlish we 

 have now found that the line of the supposed trench is in 

 reality a line of closely-placed deep pot-holes, running nearly 

 at right-angles to the course of the valley. These pot-holes 

 are connected by a narrow joint or fissure, which dies out 

 eastward, so that the last pot-hole excavated by Mr. Mansel- 

 Pleydell shows a smooth unbroken wall on its eastern side, 

 and the chalk here rises nearly to the surface ; but beyond 

 is another small though deep pipe, in which, as already men- 

 tioned, was found a lining of black clay. In their inception 

 this line of pits was evidently nothing but a row of percolation 



