• E. E. Eotvorth—A Great Post-Glacial Flood. 423 



potent transporting agency to explain these blocks of stone and 

 chalk ; but independently of ice on this scale being quite incon- 

 sistent with the whole life-surroundings, zoological and botanical, of 

 the period with which we are dealing, we cannot understand how it 

 is to explain the existence of unweathered sandstone blocks,. etc. 

 If the condition of these masses and of the soft lumps of chalk is 

 inconsistent with their having been rolled in a river, a fortiori 

 is it inconsistent with their having been at the mercy of such 

 a triturating element as ice, which it is the fashion now to 

 bring in like the giant in children's toy-books, to solve every in- 

 tractable riddle ? The boulders which form moraines, which charac- 

 terize the Boulder-clay, and which are found wherever we have 

 unmistakable ice-action, bear a very different facies. The same con- 

 clusion seems to follow from the fact that among these blocks are 

 never found fragments of rock foreign to the valley of the Somme, 

 no erratics which have been brought from another hydrographical 

 basin (Antiquity of Man, p. 182). The removal of these unworn 

 blocks, and the accompanying pieces of friable chalk, from the 

 adjoining plateaux whence they have been derived, it seems to me, 

 must inevitably be assigned, not to ice, but to a great wave of trans- 

 porting water. The same agent, lastly, accounts for the contorted 

 and twisted, ploughed-up and disturbed beds, of which such excellent 

 sections have been published by the Nestor of these inquiries, to 

 whom we are all under such immense obligations, Mr. Prestwich, 

 notably one on page 299 of his Memoir in the Phil. Trans. 1861, and 

 by others. It explains, lastly, the sorting of the materials in the 

 terraces, the heavier gravels below, and above them the covering of 

 sands and pure loam. 



It seems to me that every way we look at the problem as 

 illustrated by the valley terraces, we must face one conclusion if 

 we are to adequately explain the facts, namely, that of a wide- 

 spread flood. Although I cannot for a moment believe in Mr. Tylor's 

 Pluvial period, I must endorse the sentence in which he says "that 

 we ought to judge of the height of a flood by means of the 

 debris it has left, and not by any theoretical notions of our own " 

 (op. cit. p. 124). 



Again, excepting always the use of the word ' river,' and replacing 

 it by the neutral word 'floods,' Mr. Geikie's words in the following 

 sentence seem to be most just as describing the deposits in question. 

 He says, "The rivers of the Pleistocene period often assumed a tor- 

 rential character Their torrential character is shown by the 



coarseness of much of the gravel, the flints being often very little 

 rolled — by the absence of mud sediment, and by the confused and irre- 

 gular disposition of the bedding — all bespeaking the action of tumult- 

 uous waters that hurried along promiscuous heaps of stones and 

 scattered them in confusion over the slopes and bottoms of the valleys, 

 while the finer sediments were swept away in suspension. When the 

 water of the flooded river was in less commotion, the finer sediment 

 held in suspension would be deposited, and this, as Professor 

 Prestwich points out, has doubtless been the origin of many of 



