1862.] RAMSAY GLACIAL ORIGIN OF LAKES. 195 



Neuchatel, at the point on the Map marked B, prove that this glacier 

 was about 2200 feet thick where it abutted on the mountains ; and, 

 where it first flowed out upon the plain at the mouth of the vallej 

 of the Ehone, the ice, according to Charpentier, must have been 

 at least 2780 feet thick *. Add to this the depth of the lake, 984 

 feet, and the total thickness of the ice must have been about 3764 feet 

 at what is now the eastern part of the lake, fig. 2 f. I conceive, then, 

 that this enormous mass of ice, pushing first north-west and then partly 

 west, scooped out the hollow of the Lake of Geneva most deeply in its 

 eastern part opposite Lausanne, where the thickness and weight of ice, 

 and consequently its grinding power, were greatest. This weight de- 

 creasing as it flowed towards the west, from the natural diminution 

 of the glacier, possessed a diminishing eroding power, so that less 

 matter was planed out in that direction, and thus a long rock-basin 

 was formed, into which the waters of the Ehone and other streams 

 flowed when the climate ameliorated and the glacier retired. 



LaTce of Neuchdtel. — The basins of the Lakes of IS'euchatel, Bienne, 

 and Morat were, I consider, hollowed out in a similar manner, dif- 

 fering in poiuts of detail. ISTear the Lake of Keuchatel, on the flank 

 of the Jura, the fan-shaped end of the Ehone glacier (No. 1) attained 

 its greatest height, swelled in size and pressed on as it was by others 

 that descended from the north snow-shed of the mountains between 

 the Oldenhorn and the great snow-field above Grindelwald. Accord- 

 ing to estimates based on the highest ice-stranded boulders, the ice 

 rose 2203 feet above the present surface of the lake. The lake is 

 now 1427 feet above the sea, and 480 feet deep ; and the Lake of 

 Bienne is 1425 feet above the sea, and 231 feet in depth. The 

 bottom of the Lake of Neuchatel is thus 947 feet above the sea. 

 Unless the gravel, therefore, on the banks of the Aar, immediately 

 east of the latter, be over 480 feet deep, the hollow of the lake 

 near its immediate bounds is a true rock-basin ; for on the north, 

 south, and west it is surrounded by solid Secondary and Miocene 

 rocks. Even if the rock does not rise close to the surface in the 

 river near the lake, still, at Solothurn, strata in place come close 

 to the river-bank on both sides, the river being 1414 feet above the 

 sea. Under any circumstances there must therefore be a long, deep 

 trough between Solothurn and the rocks a little south-west of the 

 Lake of Neuchatel. How was this basin formed ? When the gla- 

 cier, debouching from the valley of the Ehone, spread out like a fan 

 and pressed forward till it abutted on the Jura, its onward progress 

 was stopped by that mountain; and direct further advance being 

 hindered, the ice spread north-east and south-west, to the right and 

 left, and being as a whole thickest and heaviest above the area where 

 the lake now lies, a greater quantity of the Miocene strata on which 

 it rested must have been ploughed out there than further on towards 

 the north-east and south-west ends of the glacier, towards which 



* The Lake of Geneva is 197 feet lower than the Lake of Neuchatel. The 

 glacier first surmounted the hills between Lausanne and Vevay, and then flowed 

 down the general slope northwards to the Jura. 



t This diagram is on a true scale both horizontally and vertically. 



