456 Professor Hull — On the Glaciation of Norway. 



islands, scored and grooved in parallel lines over extensive tracts, 

 caa be due to wave or current action. Such action would not 

 result in grooving the rocks in rectilinear directions at right angles, 

 or oblique, to the coastline, but sometimes even parallel thereto. As 

 a matter of fact, however, as far as my observation goes (and I have 

 visited a considerable extent of shore-line in all parts of the British 

 Isles and elsewhere) the sea never does sculpture rock-surfaces in 

 the same manner as does glacier-ice, either past or present. Ice- 

 action on rocks is sui generis, and sea-action, when opportunity offers, 

 only tends to obliterate, not to produce, the sculptured surfaces. 



But notwithstanding our author's statement, there really does 

 exist direct evidence of the former higher level at which the Scan- 

 dinavian region, including the British Isles, once stood ; evidence 

 to which the late Mr. Godwin-Austen was (if I recollect aright) the 

 first to call attention, and which was afterwards more fully worked out 

 by Professor T. Rupert Jones ; I refer to the submerged river system 

 of the North Sea plateau. It is well known from soundings that the 

 British Isles and the Scandinavian promontory are planted on 

 a platform of an average depth of 100 fathoms, beyond which 

 the descent is rapid to deeper levels. This platform is known to be 

 traversed by channels continuous with some of the existing larger 

 rivers, which converge towards a main channel, just like tributaries 

 to a large river, and this channel, pursuing a northerly direction, 

 opens out into the Atlantic at the edge of the plateau.^ There can 

 be no doubt but that these channels were originally those of a river 

 system at a time when the North Sea, or German Ocean, was a land- 

 surface, and stood at least 600 or 700 feet higher than at present, 

 how much higher we cannot tell. But it is worthy of notice, that 

 the extent of the elevation corresponds very closely with that of the 

 depression which may be inferred in the cases of Scandinavia and 

 the British Isles from the levels of shell-bearing beds, amounting 

 altogether to a combined rise and fall of 1,200 to 1,400 feet. 



Here, then, is the " direct evidence " of which my distinguished 

 friend stands in need ; I do not doubt that he will give it, as 

 also the glacial deflections of Scotland, due consideration. 



It now remains to show that the phenomena of submergence and 

 glaciation are not incompatible with each other. The author appears 

 to me to have commenced his historical essay on the Glacial period 

 at Chapter II. The introductory Chapter I, which would deal with 

 elevation and glaciation, he has strangely overlooked. True, that 

 towards the close of this part of his essay he shows by the passage 

 already quoted, that he has had an inkling of an epoch antei'ior to 

 that of submersion. Let him give the introductory chapter in the 

 history of the Glacial period fair consideration, and then he will see 

 how well it fits in with that epoch to which his mind has been so 

 forcibly directed. It is many years since I held the views for which, 



1 In the paper on " Another possible Cause of the Glacial Epoch," to which the 

 Council of the Geoloo-ical Society thought proper to refuse publication, I adduced the 

 case of this submerged plateau as being a representative of those of the eastern coast 

 of An e:ica and the Antilles so ably worked out by Professor Spencer. 



