160 SCIENCE IN SHORT CHAPTE11S. 



glaciers. As these suggestions and corrections may be inter- 

 esting to others, as they have been to myself, I will here state 

 them in outline. 



The most prominent and puzzling reflection or conclusion 

 suggested by reading Mr. Geikie's description of the glacial 

 deposits of Scotland was, that the great bulk of them are quite 

 different from the deposits of existing glaciers. This reminded 

 me of a previous puzzle and disappointment that I had met in 

 Norway, where I had observed such abundance of striation, 

 such universality of polished rocks and rounded mountains, and 

 so many striking examples of perched blocks, with scarcely any 

 decent vestiges of moraines. This was especially the case in 

 Arctic Norway. Coasting from Trondhjem to Hammerfest, 

 winding round glaciated islands, in and out of fiords banked 

 with glaciated rock-slopes, along more than a thousand miles 

 of shore line, displaying the outlets of a thousand ancient 

 glacier valleys, scanning eagerly throughout from sea to sum- 

 mit, landing at several stations, and climbing the most com- 

 manding hills, I saw only one ancient moraine that at the Ox- 

 fjord. station described in " Through Norway with Ladies." * 



* The terminal moraine at the Oxfjord station, which I have al- 

 ready mentioned as the only ancient example of an ordinary moraine 

 that I have seen in Arctic Norway, was, of course, a special object of 

 interest to me. Further observation showed that it does not merely 

 consist of the heap of stones I noticed in 1856, which appears like a 

 disturbed talus cut through, and heaped up at its lower part, but 

 that there is another moraine adjoining it, or in continuation with it, 

 which is covered with vegetation, and stretches quite across the 

 mouth of the valley. The Duke of Roxburgh, who is well acquainted 

 with this neighborhood, having spent sixteen summers in Arctic 

 Norway, was one of our fellow-passengers, and told me that this 

 moraine forms a barrier that dams up the waters of a considerable 

 lake, abounding with remarkably fine char. I learned this just as the 

 packet was starting, too late to go on shore even for a few minutes, 

 and obtain a view of this lake and the valley beyond. This I regret, 

 as it might have revealed some explanation of the exceptional nature 

 of this moraine. It would be interesting to learn whether it belongs 

 to the greater ice age, or to that period of minor glaciation that 

 fashioned the farm patches already described. The formation of the 

 lake is easily understood in the latter case. It is only required that 

 such a minor reglaciated valley as one of these should be of larger 

 magnitude and of very gentle inclination at its lower part, so that 

 the secondary glacier should die out before reaching the present sea- 

 shore. It would then deposit its moraine across the mouth of the 

 valley, and this moraine would dam up the waters which such a val- 

 ley niust necessarily receive from the drainage of its hilly sides. 

 Llyn Idwal, in North Wales, is a lake thus formed. 



