436 H. H. Kowortli — Tracer of a Great Post- Glacial Flood. 



Mr, John Evans. According to tliis theory, the gravel which 

 is so conspicuous in Hampshire and the neighbouring districts 

 is of fluviatile origin and marks the bed of an ancient river, 

 vs^hich once flowed in a direction parallel to the present coast-line, 

 and of whose channel the present Solent was once a part. I confess 

 that I am utterly bewildered how to reconcile this theory with the 

 facts as I have examined them with patience and care for many days 

 in this part of England. In the first place, the gravel presents no 

 single feature which seems to me compatible with its having been of 

 fluviatile origin. It contains no debris of fluviatile organisms, no 

 remains of shells, etc., etc., whicli lived in such a river. Such 

 remains are common in river gravel properly so-called. Mr. Belt 

 says, " "When travelling in Eussia, I examined the sands and gravels of 

 the beds of the larger rivers. These rivers are frozen over for 

 several months in the year, and it seemed likely that the conditions 

 would be somewhat similar to those that are supposed to have 

 existed in the valley of the Thames at the close of the Glacial period. 

 Much of the sand and gravel from the rivers of Southern Russia 

 was used for ballasting railways, so that I had many opportunities of 

 examining it. I found it in every case full of river-shells, and some- 

 times one-half of the whole mass seemed to be shells. There were 

 three species of TJnio, and the little Neritina. fluviatilis, especially 

 abundant. Where gravel from the bed of the Thames is now 

 dredged up, it also contains many shells." In the Angular drift we 

 find no river-shells, but on the other hand, as in the loess and the 

 loams that have occupied us in previous papers, we have many 

 remains of a purely terrestrial origin, land-shells, bones of animals, 

 and worked flints, the debris of primitive man. 



If we turn from the contents of the beds we are describing to 

 their texture, we shall be even more impressed with the difficulty 

 of assigning a fluviatile origin to them. A very lai'ge proportion of 

 the flints in these gravels is remarkable for being unrolled and 

 nnweathered. The fractured edges are sharp and unrubbed. Mr. 

 Searles Wood, to whom we are all so exceedingly indebted for 

 having brought light into the chaotic regions of surface geology, 

 describes very graphically the nature and condition of these flints. 

 He says, speaking of the mixture of the rolled pebbles from the 

 Tertiary beds with the unrolled flints : " The especially noteworthy 

 feature connected with this intermixture is that the pebbles and the 

 a,ngular flints present no intermediate grades of rolling to connect 

 them ; so that it is obvious this admixture of angular flint and 

 Tertiary pebble cannot, in finding its way to the positions it 

 occupies, have undergone any considerable or repeated amount oficear 

 hy transport. Instances occur, moreover, in which chalk fragments 

 have occurred in this intermixture. Considering how impossible it 

 is for chalk to sustain without dissolution any long -continued aqueous 

 action, this circumstance is also of much importance." Speaking of 

 these facts Mr. Wood says : " This feature seems to me repugnant 

 to any presumption that these pebbles have settled down into their 

 present places by successive transport from higher to lower levels 



