22 TKACES OF THE GREAT ICE AGE IN DERBYSHIRE. 



Stream to its termination, and although this distance is not 

 considerable in the case of the now shrunken Swiss glaciers, it 

 would be considerable at the time of their maximum extension. 



An examination of the Swiss valleys shows that the glaciers 

 now occupying them are but the ghosts of their former selves. 

 Taking, for example, the Rhone Valley, we find ice-markings on 

 the Schneestock (near the source of the glacier) at a height of 

 11,500 feet above sea level, or 1,500 feet above the present level 

 of the glacier. At Fiesch, about twenty miles below, the ice 

 was about a mile in thickness ; while fifty miles lower, where the 

 glacier was deflected sharply to the north, it was scarcely less 

 thick. On reaching the wide part of the valley, just above the 

 Lake of Geneva, the glacier spread out as a wide and nearly level 

 sheet of ice transporting Alpine boulders to the flanks of the 

 Juras, landing them at a height of 3,000 feet above the level of 

 the lake. Here one branch spreading southwards was joined 

 by a tributary from Mont Blanc at the foot of the lake, and a 

 north-easterly branch was joined in the vicinity of Berne by the 

 ice-stream which descended from the northern flanks of the 

 Bernese Oberland through the valley of the Aar. These united 

 streams filled the whole valley with ice as far down as Soleure. 

 Near this place is a block of granite, weighing about 4,100 tons, 

 brought hither from the Valais, a distance of some 115 miles. 



South of the Alps, from the flanks of Mont Blanc and Monte 

 Rosa, enormous glaciers descended into the Val d'Aosta, and 

 spread out over the plains of Lombardy, leaving huge moraines, 

 some of which are 1,500 feet in height. 



Turning to our own islands we find abundant traces of this 

 cold period Scotland was completely enveloped in a sheet of 

 ice, which extended to the west of the Hebrides, and it has been 

 shown how the characteristic rounded forms of the Scotch 

 mountains are due to this. The ice-sheet moved out from the 

 high lands in a westerly and southerly direction, a movement to 

 the east being checked, in the period of greatest cold, by an 

 enormous glacier which came from Scandinavia, filling up the 

 North Sea and deflecting the ice from the eastern slopes of 



