455 
furrowed, and scratched. In several places there are veins of hard 
quartz standing three or four inches above the general surface of 
the smoothed rocks, on the south side of which veins the furrows 
generally stop, as if the furrowing agent had been obstructed by 
them. A model illustrating the phenomenon was exhibited. The 
direction of the furrows and scratches is here due N. and S. 
The locality is 1300 feet above Chamouni, and 4725 feet above 
the sea. 
It was mentioned that transported alpine blocks occur on both 
sides of the valley here, and all the way down to the Petit Saleve 
mountain (near Geneva), distant about thirty miles, the S.E. slope 
of which faces the Arve valley. These blocks cover the hill to its 
top, which is 2800 feet above the sea. 
The author mentioned having visited the glaciers in the higher 
parts of Chamouni valley, and that he had satisfied himself of the 
fact that an ancient glacier had passed northwards into the Val 
Orsine. He considered that the whole of the upper part of Cha- 
mouni valley had been filled with ice, which had flowed, not down 
that valley, but through the Yal Orsine. The pass into this valley 
must at that time have been at least 1000 feet lower than the ob- 
struction across the valley of Chamouni caused by the Mer de Glace. 
Some account was then given of the marks of ancient glaciers in 
the valley of the Rhone ; and attention was more particularly drawn 
to the enormous deposits of gravel, sand, and clay throughout low 
Switzerland, and to the important fact, that the great transported 
blocks on the Jura, and elsewhere in low Switzerland, are generally 
imbedded in these pleistocene strata. 
It was also mentioned that the transported blocks are at greater 
absolute heights near the mouth of the valley of the Rhone than 
anywhere else ; and that these heights, both for the blocks and for 
the gravel and clay beds, diminish gradually towards the west. 
The sloping line of the latter along the south bank of Lake Leman 
is a striking object from Lausanne. 
The author expressed his conviction, from the phenomena referred 
to, that glaciers had formerly descended to the low country through 
the valleys of the Arve and Rhone, bringing down and spreading in 
all quarters blocks and detritus. The only difficulty felt was as to 
the cause of the low temperature necessary to produce glaciers on 
so great a scale. 
3 r 
YOL. IV. 
