260 Sir S. H. Eoicorth — Surface Geology of N. Europe. 



but to explain them and their portage when anything but a glacial 

 climate is testified to by the mollusca occurring with them. It 

 seems, therefore, impossible to appeal to ordinary rivers in order to 

 explain these angular blocks ; much more so is it difficult to account 

 for their portage by subglacial or supraglacial rivers. In neither 

 case do such rivers carry ice-rafts. Nor can we see how ice-rafts 

 could arise in either of them. Ice-rafts are the broken pieces of ice 

 which once covered subaerial rivers. The only ice which covers 

 subglacial rivers is the tunnel of ice through which they flow, while 

 supraglacial rivers do not freeze on their surface, but cease to exist 

 entirely in winter, for they are the result of the melting of the 

 surface of the glaciers and nothing more. 



In every way we view the fluviatile theory of the origin of 

 the asar it seems to collapse when analyzed, and if T could be 

 astonished at anything which the glacial geologists choose to 

 formulate I should be greatly surprised at its continued existence 

 in their textbooks. The time is assuredly coming when the 

 reputations which have been built up on such science will as 

 assuredly collapse. No wonder a desperate struggle is made to 

 maintain them in some quarters, and a portentous silence prevails in 

 others. Putting aside the fluviatile theory, whither are we to turn for 

 an explanation of the asar but to the primitive theory of all ; the 

 one which commended itself to the earliest Swedish geologists, 

 namely, that they are in some way or other the result of the action 

 of the sea during a period of submergence. Thus Swedenborg urges 

 that the existence of a former widespread ocean is proved by the 

 mixture of substances in the asar of sand and gravel, of clay, and 

 large masses of rock and boulders. He urges further that the 

 polished and triturated appearance of the stones in them was 

 the work of the sea, and the slope of the ridges he thinks proves 

 that they were thrown up by the sea into great accumulations, and 

 so formed into lengthened ridges. He argues that the fact of the 

 ridges running north and south shows that the same winds prevailed 

 in Diluvian times as do now, and he appeals to the principle of 

 hydraulics to show that the sea could have done this kind of work. 

 Eobert, writing as far back as 1836, says : " Les coUines de sable 

 du N., ou osars comme on les appelle vulgairement, ont ete formees 

 au sein des eaux de la mer par I'eflFet des courants, phenomene 

 encore en action." The sea in its normal attitude was appealed 

 to to explain the asar by two other acute, later writers, namely, 

 Ch. Martins and Eobert Chambers. The former, an extreme 

 champion of the Glacial theory, says : " The asar form one of the 

 numerous proofs of the immersion and emergence of the 



Scandinavian surface The asar were the work of 



the sea during the time of the Scandinavian immersion. They 

 are veritable dunes (the Bevler of the Jutland coast), with a cross- 

 bedding in their stratification, formed by the waves which traversed 

 these ramparts and there deposited the pebbles and sand wliich it 

 had removed from the bottom of the sea. The pebbles in the asar 

 are never striated. If they ever had any striae these have been 



