Alpine Valleys in relation to Glaciers, 17,3 



during the Great Ice-Age. The author tests this hypothesis by 

 applying it first to the valley of the Visp, of the eastern arm of 

 which, and of the ' hanging valley ' like a gigantic corrie, where 

 Saas Pee is situated, he gives a description, pointing out that all 

 parts are so connected that any separate explanation of their form 

 is impossible. 



To obtain an idea of the condition of the Alps in Middle and Later 

 Tertiary times, we may consider the effect of alterations of tempe- 

 rature, on the assumption (which, as he shows, is not likely to be 

 seriously incorrect) that the altitude of the Alps during the greater 

 part of their existence has remained unchanged. A rise of tempe- 

 rature of from 6° to 7° Pahr. would have the same effect as 

 lowering the district by 2000 feet ; a rise of 10° would correspond 

 with 3000 feet. In the latter case the Pennine chain about the 

 headwaters of the Visp would be comparable with the range from 

 Monte Leone to the Ofenhorn. With a rise of 14° glaciers would 

 almost vanish from the Alps, for the snow-line would then be at 

 12,000 feet above sea-level. Thus glacial action in the Oligocene and 

 Miocene ages would be a negligible quantity, and it would gradually 

 become sensible during the Pliocene ; but glaciers would not invade 

 valleys now free from them until the temperature was some degrees 

 lower than it is at present — in other words, can have occupied these 

 during only a small portion of their existence. 



The author passes in review a number of other Alpine valleys, 

 which lead to the same conclusion. He calls attention once more 

 to the connexion of cirques with valleys, to the impossibility of 

 referring the former to glacial action, and to the unity exhibited by 

 all parts of the Alpine valleys, touching upon some structural diffi- 

 culties which Prof. Davis has been content to meet with hypotheses. 

 Alpine valleys in all parts, as the author shows, indicate by their 

 forms meteoric agencies other than glaciers, which can only have 

 acted for a comparatively short time and have produced little more 

 than superficial effects. 



3. ' The Origin of some " Hanging Valleys " in the Alps and 

 Himalaya.' By Prof. Edmund Johnstone Garwood, M.A., F.G.8. 



Lateral valleys which enter the main valley marked by discordant 

 grades in the Jongri district of the Sikhim Himalaya have been 

 attributed by the author to Pleistocene elevation and super-erosion 

 of the main valley by water. Similar valleys in the Val Ticino 

 have recently been attributed to overdeepening of the main valley 

 by ice. The author shows that there is no real proof of this 

 in fact the evidence seems strongly to point to fluviatile, and not 

 glacial erosion of the main valley. This is shown by the overlapping 

 profiles and river-gorges situated both above and below some of 

 these 'hanging valleys,' and by the fact that a greater relative 

 amount of orosion has taken place towards the upper end oi the 

 main valley than at the lower, where the mouths of the * hanging 

 valleys ' are less elevated. The overdeepening of the main valley 

 is attributed to an epeirogcnic uplift in Pleistocene times, con- 

 sequent on the melting-away of the ice-cap, the lateral valleys 

 being merely tilted sideways. This effect is intensified by the 



