300 DIRECTION TAKEN BY THE ERRATICS, CHAP. xv. 



the principal icy mass moved straight onwards in a direct line 

 towards the hill of Chasseron, G (precisely opposite F), where 

 the Alpine erratics attain their maximum of height on the 

 Jura, that is to say, 2,015 English feet above the level of the 

 Lake of Neufchatel, or 3,450 feet above the sea. The granite 

 blocks which have ascended to this eminence G, came from 

 the east shoulder of Mont Blanc, A, having travelled in the 

 direction B, F, G. 



When these and the accompanying blocks resting on the 

 south-eastern declivity of the Jura are traced from their 

 culminating point a, in opposite directions, whether westward 

 towards Geneva, or eastwards towards Soleure, they are found 

 to decline in height from the middle of the arc G, towards 

 the two extremities I an<J K, both of which are at a lower 

 level than G, by about 1,500 feet. In other words, the 

 ice of the extinct glacier, having mounted up on the sloping 

 flanks of the Jura in the line of greatest pressure to its highest 

 elevation, began to decline laterally in the manner of a pliant 

 or viscous mass, with a gentle inclination, till it reached two 

 points distant from each other no less than 100 miles. 



In further confirmation of this theory, M. Gruyot observed 

 that fragments derived from the right bank of the great valley 

 of the Rhone, c, d, e, are found on the right side of the great 

 Swiss basin or strath, as at I and m, while those derived from 

 the left bank, p, h, occur on the left side of the basin, or on 

 the Jura, between G and i; and those again derived from 

 places farthest up on the left bank and nearest the source of 

 the Rhone, as n o, occupy the middle of the great basin, con 

 stituting, between m and K, what M. Gruyot calls the frontal 

 or terminal moraine of the eastern prolongation of the old 

 glacier. 



A huge boulder of talcose granite, now at Steinhoff, ten 

 miles east fromK, or Soleure, containing 61,000 cubic French 

 feet, or equal in bulk to a mass measuring 40 feet in every 



