an the Ice of Glaciers. 85 
to me that the wish which had been expressed by very many 
of those to whose judgment I am most willing to defer, that 
I should make such a detailed communication, was one with 
which, in my official position as Secretary, and having in some 
degree the control of the order and distribution of business, I 
could not properly comply. 
I do not, however, relinquish the idea of laying before the 
Society, and even at considerable length, the conclusions which 
I may ultimately form respecting the great physical and geo- 
logical questions now at issue, and the facts and reasonings 
upon which these conclusions are founded. The Glacier Theory, 
whether it regards the present or past history of those mighty 
and resistless vehicles of transport and instruments of degra- 
dation, yields to no other physical speculation of the present 
day in grandeur, importance, interest, and, I had almost said, 
novelty. I look forward to the prospect, which I hope may 
be realized, of extending much farther, during another sum- 
mer, my direct observations and experiments, and in the mean 
time I desire to prepare myself for the task, by a thoughtful 
review of the experience I have already had, and a close ana- 
lysis of what has been already argued and written upon the 
subject. Should the result be successful, the Society may, a 
year hence, expect the communication of it. For the present 
I mean to confine myself to the description of a single fact, 
which appears generally, if not universally, to have escaped 
the notice of former travellers amongst the Glaciers. 
On the 9th of August last (1841) I paid my first visit to 
the Lower Glacier of the Aar, upon or near which I spent the 
greater part of three weeks in company with Professor Agas- 
siz of Neufchatel, and Mr J. M. Heath of Cambridge. It is 
surprising how little we see until we are taught to observe. 
I had crossed and re-crossed many glaciers before, and attend- 
ed to their phenomena in a general way; but it was witha 
new sense of the importance and difficulty of the investiga- 
tion of their nature and functions that I found something to 
remark at every step which had not struck me before; and 
even in the course of the walk along our own glacier (as we 
considered that of the Aar, when we had taken up our habi- 
tation upon it), we found on its vast and varied surface some- 
thing each day which had totally escaped us before. It was 
