Notice of Prof. Forbes 's Travels in the Alps. 185 



The harder fragments are set in the ice as the emery is set in the 

 wheel of the lapidary, and " the gravel sand and impalpable mud are 

 the emery of the glacier." The glaciers are always wearing, scratch- 

 ing, marking, and polishing the sides of the rocks against which they 

 are pressed in their downward progress, and these lateral grooves are 

 often visible at great elevations, even far above any existing glaciers. 

 This is remarkably exhibited in the denies and mountain cliffs between 

 the primary Alps and the secondary Jura mountains. 



These ranges are parallel with the great valley of Switzerland which 

 lies between them and is dotted with lakes ; the direction of the valley is 

 N. E. and S. W. : it is about thirty English miles wide, but the distance 

 from the highest part of the Alps to the highest part of the Jura, is not 

 less than eighty miles. " Near to the great gap in the main chain formed 

 by the valley of the Rhone we have the lake of Neufchatel, with moun- 

 tains of secondary limestone, in some parts of the age of the English 

 oolite, and rising to about three thousand feet above the valley." Upon 

 the slope of this range, and at a considerable elevation above it and 

 facing the valley of the Rhone, there are extensive deposits of angular 

 blocs of granite, of the kind found on the eastern side of Mont Blanc, 

 the nearest spot where these rocks occur in situ, and no rock in the 

 least similar is found any where in the Jura, or nearer than that part 

 of the Alps already named, " and which may be sixty to seventy miles 

 distant as the crow flies." " A great belt of these blocs occupies a 

 line, extending for miles, at an average height of eight hundred feet 

 above the level of the lake of Neufchatel, and above and below that 

 line they diminish in numbers, although not entirely wanting." Multi- 

 tudes of them have been broken up and removed for architectural pur- 

 poses, or merely to clear the land, and many are concealed among the 

 trees of the mountain forests, " but wherever seen, they fill the mind 

 with astonishment, when it is recollected that as a matter of certainty, 

 these vast rocks, larger than no mean cottages, have been removed 

 from the distant peaks of the Alps, visible in dim perspective amidst 

 the eternal snows, at the very instant when we stand on their debris. 

 The celebrated bowlder called Pierre a Bot, or toadstone, in this vicin- 

 ity, about two miles west of Neufchatel, is fifty feet long, twenty wide, 

 and forty high, and contains forty thousand French cubic feet. It 

 forms a stupendous monument of power. It is impossible to look at it 

 without emotion, after surveying the distance which separates it from 

 its birth-place." There are besides in the neighborhood, hundreds and 

 thousands of truncated blocs, some small and rounded, but a vast num- 

 ber exceeding a cubic yard in contents and perfectly angular, or at 

 least with only their corners and edges slightly worn, but without any 

 appearance whatever of considerable attrition, or any violence having 



Vol. xlvi, No. 1.— Oct.-Dec. 1843. 24 



