IV THE ICE AQK AND ITS WORK 79 



round to the right across the Lake of Neufchatel, and 

 extended at leastas far as Soleure, a distance of about 

 90 miles. (See Map at page 128.) To do this it must 

 have ascended 500 or 600 feet to the country around 

 Fribourg, and before reaching Soleure must have passed 

 over a hill 300 or 400 feet higher. Yet on the flanks of 

 the Jura above Soleure there are erratics which have been 

 carried on the surface of the glacier from the east side of 

 the valley below Martigny ; and close to Soleure itself there 

 are remains of a terminal sub-glacial moraine of compact 

 boulder-clay. Sir Charles Lyell describes this as — 



"an unstratified mass of clay or mud, through which a variety of 

 angular and rubbed stones were scattered, and a marked proportion 

 of the whole were polished and scratched, and the clay rendered so 

 compact, as if by the incumbent pressure of a great mass of ice, that 

 it has been found necessary to blow it up with gunpowder in making 

 railway cuttings through part of it. A marble rock, of the age of our 

 Portland stone, on which this old moraine rests has its surface 

 polished like a looking-glass, displaying beautiful sections of fossil 

 shells, while occasionally, besides finer stripe, there are deep recti- 

 linear grooves, agreeing in direction with the course in which the 

 extinct glacier moved according to the theory of M. Guyot before 

 explained." ^ 



It is evident that, to have produced such effects as are 

 here described, the glacier must have extended much 

 beyond Soleure, and have been very thick even there. It 

 thus proves to demonstration that a glacier can travel for 

 100 miles over a generally level country, that it ca7i pass 

 over hills and valleys, and that, even near its termination, 

 it ca7i groove, and grind, and polish rocks, and deposit 

 large masses of hard boulder-clay. And all this was done 

 by a single glacier issuing from a comparatively narrow 

 valley, and then spreading out over an area many times 

 greater than that of its whole previous course. In this 

 case it is clear that such a vast mass of ice, constituting a 

 veritable ice-sheet on a small scale, could not have derived 

 its motion solely from the push given to it by the parent 

 glacier at St. Maurice. Neither could gravitation derived 

 from the slope of the ground have affected it, for it passed 



The Antiquity of Man, 4th edition, p. 349. 



