412 . DYNAMICAL GEOLOGY. 

their native valleys, across plains, valleys, and even considerable 
ranges of hills. Such “ erratics ” (Findlinge) not only abound in the 
Swiss valleys, but cross the great plain of Switzerland, and appear in 
numbers high upon the flanks of the Jura. Since the latter mountains 
consist chiefly of limestone, and the blocks are of various crystalline 
rocks belonging to the higher parts of the Alps, the proof of trans- 
port is irrefragable. Thousands of them form a great belt of boulders 
extending for miles at an average height of 800 feet above the Lake 
of Neufchatel (Fig. 145). These consist of the protigine granite of 



Fic. 145.—Pizrre A Bot—A GRANITIC BLOCK FROM THE Mont Biane RANGE, 
STRANDED ABOVE NeuFcHATEL (J. D. ForBEs). 
the Mont Blanc group of mountains, and must have travelled at 
least 60 or 70 miles. One of the most noted of them, the Pierre a 
Bot (toad-stone), which lies about two miles west of Neufchatel, 
measures 50 (French) feet in length by 20 in width, and 40 in height. 
It is estimated to contain 40,000 cubic feet, and to weigh about 3000 
tons... The celebrated “blocks of Monthey ” consist of huge masses 
of granite, disposed in a belt, which extends for miles along the 
mountain slopes on the left bank of the Rhone, near its union with 
the Lake of Geneva. On the southern side of the Alps similar 
evidence of the transport of blocks from the central mountains is to 
be found. On the flanks of the limestone heights on the further 
side of the Lake of Como, blocks of granite, gneiss, and other 
crystalline rocks lie scattered about in hundreds (Fig. 146), 










Fic. 146.—ANGULAR ERRATIC BLOCK ON THE NORTH SIDE OF THE ALPI DI PRAYOLTA 
LAKE or Como (B.). 
Before the numerous facts had been collected and understcod 
which prove a former great augmentation in the size of the Alpine 
' Forbes, “ Travels in the Alps,” p. 49. 
