272 



THE GEOLOGIST. 



appear to have descended into the sea during the glacial period. The phe- 

 nomena of Sutherlandshire appear to have forced such an analogy on the mind 

 of Sir 11. Murchison, when lately exploring this region. Glacial vestiges are 

 no less marked over the rugged and inhospitable island of Skye. 



Professor Agassiz is of opinion that the parallel roads of Glenroy, near the 

 foot of Ben Nevis, are attributable to a lateral glacier having been projected 

 across the valley, near Bridge Roy, and another across the valley of Glen 

 Speane. 



By this means glacier lakes were formed, along whose margin the stratified 

 terraces of gravel were produced, which are now seen to line the flanks of the 

 valley at a perfectly horizontal level through several leagues. The subsequent 

 melting of the glaciers has entirely obliterated any traces of the agent by means 

 of which the waters were pent up. Mr. Darwin, however, takes a different 

 view of the subject, considering that the parallel roads are marine terraces, 

 formed during the submergence of the land to a depth of one thousand two 

 hundred and fifty feet, their present elevation. 



Professor Agassiz and Dr. Buckland considered not only that glaciers once 

 existed in the British Islands, but that large sheets of ice (nappes) covered all 

 the surface of the districts surrounding the Highland groups. This opinion 

 is founded on the wide extent to which unstratified gravels, perched blocks, 

 and polished surfaces in situ are distributed over the districts adjacent to the 

 centres of distribution. It is now generally allowed that floating ice, or rather 

 swimming ice, has played a more important part in producing these phenomena 

 than was supposed by the founders of the glacial theory. It is, indeed, an 

 almost unsolved problem, how we are, in all cases, to distinguish between the 

 effects of icebergs charged with stones scraping along the sides and bottoms of 

 the channels through which they float, and the effects of subaerial glaciers. 

 If of large size, and impelled by prevalent winds or currents in one general 

 direction, they would produce polished, grooved and rounded surfaces on the 

 rocks with which they would come in contact, and leave behind blocks and 

 debris strewn so as to resemble the matter of moraines. At the same time there 

 are several classes of objects which could only have been produced by sub- 

 aerial glaciers, and others which bear the unmistakable impress of aqueous 

 deposition." The great object to be accomplished is the production of maps 

 showing the direction of the strise, the position of the moraines, and the limits 

 of the drift, amongst the highlands of Britain. 



Remarks upon the Flint-Implements found at Amiens and Abbeville in connection 

 with the Glacial Theory. By Adml. "Wauchope. Sweeter : Penrith. 



In this pamphlet Admiral Wauchope attempts to co-relate the flood of 

 Noah with the Glacial period; and to show that the subsidence of East 

 Florida, Newfoundland, Nova Scotia, and Labrador, by diverting the Gulf 

 Stream, was the cause of the dispersion of icebergs over Europe. One re- 

 markable statement is made at page 7, which it is highly desirable should be 

 elucidated by a more particular statement of the facts, — the passage we allude 

 to runs thus " All these events would produce a climate of equal cold with the 

 Polar regions. This would cause a rapid, and all but total extinction of the 

 huge Mammalia that browsed in thousands in the valleys and wooded plains. 

 The Irish Elk was also most likely destroyed at this time ; for I can prove its 

 having been contemporaneous with man, having seen a stone hammer sticking 

 in the skull of one, and also the heads of others which had been perforated by the 

 same kind of weapon' 1 



