

Krr«(icsoftheA! P *. -MU 



ds lo aobfiiiibai s (b bsteluolBo La. I)ept of guS?" ; 



At Aernen, -woM . . . f . 2756 feot. 



.,. Brieg (b). 2662 ... 



M.niMartigny (tf), 217" 



* . . . Monthey («), 2350 . 



oj jtidero^ a y au (^)j assuming with Charpentier that 



P3 f no - fv QI -the Lake of Geneva was covered with ice, > 2780~ x ... 

 ^A\ rf^ftfT^P which the glacier floated, 



flwollt the glacier tilled the bed of the lake to the bottom, its depth 

 opposite the Rhone would be about 3200 feet. 



mora &dt l . i5 p9adu8 logad has 



^ od i eh Preadth of the Ulacier. 



When the glacier of the Rhone had a depth of 3000 feet, its 

 breadth would probably not exceed 8 or 10 miles. It will be seen 

 in the map that the Pennine Chain f t throws out transverse ridges 

 or " spurs," separating the valleys p ny-b, each of which would have 

 its distinct glacier, but all of them tributary to the grand glacier. 

 These ridges terminate northward in peaks rising 5000 or 6000 feet 

 above the bottom of the valley, and consequently 2000 or 3000 above 

 the top of the grand glacier. The space between these peaks and 

 the northern chain v v, which defines the breadth of the grand glacier, 

 varies from 10 to 14 miles, but would not exceed 8 or 10 at the 

 surface of the ice. But after escaping from the valley of the Rhone 

 into the Swiss plain, its breadth would dilate to 30 miles, it reckoned 

 from k to/, or to 110 if reckoned from S to A. The dimensions of 

 the ancient glacier which spread the debris of the Alps over the plain 

 of Switzerland and the declivities of Mount Jura, may therefore be 

 estimated approximately as follows : — ■ 



Length from r to Mount Jura at /, 132 miles ; from r to north- 

 east terminal moraine at h, 160 miles ; and to the south-west one 

 at S, nearly the same. Breadth in the Great Valley from 8 to 10 

 miles, in the Swiss Plain 30 miles in one direction, and 110 in an- 

 other. Depth in the Great Valley from 2600 to 3000 feet, near 

 k in the plain 2780, and thence to / probably from 500 to 2000 feet. 

 (Ifio Jon td-gied odd is QI fo iftiw eteiji 



:l Btaioq i°ilm$' 1L ? aqoJ nijjJnjjom od* 1c 



Figure 11 is a section across the Great Valley and the Swiss 

 Plain from if to /. The letters correspond (except P, incorrectly 

 put for|>) ; the horizontal scale is double that of the map, and the 

 elevations here are in French feet above the sea. 



t\ The Great St Bernard — height 9000 feet above the sea. 



At o, glacial traces exist at a height of 7794 feet. 



