NOTES ON THE THICKNESS OF THE LUCERNE GLACIER, ETC. 291 



notes ill reference to certain passages which appear in the paper, 

 and they are as follows : — 



1. The " Valki/ " of the Lake of Lucerne, which valley ? This lake 

 results from a combination of old preglacial valleys, hoth longitudinal 

 and transverse, the Bay of Vri forming part of the transverse 

 system. 



2. " Beaufff and grandeur of its sojueri/" — One realizes at once 

 that the great limestone masses of the Alps cut up into far finer 

 figures than do the gneisses of the Italian side, as eWnced, for 

 instance, in the Lago Maggiore ; hence the wonderful scenery of this 

 lake which culminates in the bay of L^ri. The head of the Lake of 

 Geneva presents similar featm^es, due in a measiu'e to similar 

 geological causes. But nothing in the Alps, nothing perhaps in the 

 world, can vie with the Bay of L'ri. It derives historical interest 

 also as the birthplace of Switzerland. The Lower Cretaceous lime- 

 stones are the chief formations, drawn out along two great folds 

 invoh-ing portions of the Lower and Middle Tertiaries. 



3. '•// is hard to conceive." — With geologists there is no difficulty; 

 everybody nowadays realizes that there was such a thing as a 

 Pleistocene Glacial period, and that a mountain chain like the Alps 

 must have experienced its severity to the utmost. The whole of 

 Switzerland is full of proofs, and the sight of the transported boulders 

 of granite from the central massifs is one of the charms of a S'vviss 

 trip. Doubtless there was a Mer de Glace moving down the Vallev 

 of the Reuss and its continuation, the Bay of Uri, and there must 

 have been a fine tiu-n round the corner above Treib, where the 

 Belle Vue moraine is situated. 



4. The Glacial Origin of Lakes." — On this point there may be 

 some room for divergent opinion. Of course the idea of a gaping 

 fissiu'e due to tectonic causes, in the case of the very complex Lake 

 of Lucerne, is quite out of the Cjuestion. As I said before, the Bay 

 of L'ri forms part of one of the most striking transverse valleys of 

 erosion in the whole Alps. It was at one time a gorge of one of 

 those rivers which are almost as old as the mountains themselves, 

 and which kept deepening their channels j.>ari pami with the axial 

 elevation of the chain. Hence the Bay of Yn has been in the 

 course of its history a canon, a Mer dc Glace, and now a submerged 

 river valley, forming part of the most complex lake system in the 

 Alps. 



