298 Charles Maclaren, Esq., on the 



constantly attracts the eye. Between the hospice of the Grimsel 

 and the present glacier there are several places where you may find 

 a precipitous face of rock, of the extent of an acre, all grooved with 

 broad shallow horizontal grooves, but marked off into oblong spaces 

 by dark, vertical, and horizontal lines, caused by fissures in the rock. 

 As the granite here is in strata, resting on their edges, according to 

 M. Desor, the vertical fissures must be seams, and the horizontal 

 ones joints. When the surface of the broad grooves is sufficiently 

 near the eye to be examined, it presents fine striae. These may be 

 seen at the large smoothed area, called the Hellenplatz (figured in 

 Agassiz's 16th Plate), a little above the Handeck Waterfall, and with 

 the aid of a pocket telescope even a better view may be got, both of 

 the grooves and striae on a rock on the opposite side of the river. 



Holding it then as established, that distinctly-grooved rocks in 

 Alpine valleys are sure marks of the action of glaciers, the next 

 question is, To what altitude above the present bottom of the valley 

 of Hasli are these marks found? Now, on this point we have a dis- 

 tinct statement from Agassiz. He ascertained by barometrical 

 measurement, that on the Siedelhorn, which flanks the glacier on 

 the south, the striated rocks rise to the height of 2762 feet (English) 

 above the valley at the foot of the existing glacier. (Etudes, p. 254.) 

 There are estimates even higher than this, for Elie de Beaumont 

 admits that the upper limits of the erratic zone (marked by polished 

 rocks or travelled boulders) in the Alpine valleys indicate a depth of 

 800 or 1000 metres. — (jtemarques sur deux points de la Theorie 

 de Glaciers, 1842.) We are safe then in assuming that a glacier 

 2500 feet or more in depth occupied the valley of Hasli at an ancient 

 period. With such a depth we can well understand that the river 

 of ice might transport blocks of granite across the Brunig Pass into 

 the valley of Sarnen, which had then of course a glacier of its own, 

 with a northerly motion. The glacier of the Aar had then occupied 

 the whole of the Alpine portion of the valley, fifty miles in length, 

 which ends at Thun, and must have extended beyond it into the plain, 

 as far as Berne, where the remnants of a moraine still exist. What 

 the minimum of inclination is necessary to give motion to a glacier 

 will be afterwards considered. From the lower end of the present 

 glacier to Brienz the fall is one foot in thirty-four, or an inclination 

 rather under two degrees ; from the same point to Thun, it is one 

 foot in sixty-four, or fifty-three minutes. 



The sum of the argument derived from the preceding details may 

 be thus stated : — ibiva : & \to •: e rfoiw d 



There are two facts characteristic of existing glaciers in the Alps. 

 First, They carry down from the higher parts of the valleys masses 

 of rock often of vast size, and deposit them on the sides of the lower 

 parts of these valleys, or at their terminations. Secondly, They 

 polish and striate the rocks in contact with them. Now, in the 

 valley of Hasli, which we have been examining, we find a glacier at 



