298 Ascent of the Jungfrau in 1841. 
We therefore descended the fields of snow which stretch 
southwards, towards the Valais. The snow was perfectly ho- 
mogeneous, without any trace of rolled rocks or foreign bodies 
on its surface. ‘The crevices had almost entirely disappeared, 
or if any were still to be seen, they were on the sides of the 
valley, never extending so far as the place where we were. 
We were thus walking on with perfect security, when we re- 
marked, at some distance from us, many small openings. Cu- 
rious to know the cause, we turned aside to examine them, 
but what was our surprise, when, on looking into one of 
these sky-lights, which was not more than three inches 
broad, by a foot long, we saw that it concealed an im- 
mense precipice! And in this precipice an azure light pre- 
vailed, which surpassed in beauty, transparency, and softness, 
all that we had hitherto seen among glaciers. What a pity 
that I have not the power of reproducing, in language worthy 
of the subject, all the poetry that was embodied in this simple 
combination of light and snow! Never had I seen a more attrac- 
tive spectacle; our eyes were so fascinated by it that we did 
not at first perceive that the crust of snow which covered this 
enchanted cavern did not exceed, in this place, a few inches ; 
I do not, however, think that we ran very great danger, for the 
snow was very compact, and the sun had not softened it that 
day. After contemplating the attractive effect of this unique 
phenomenon, we were desirous likewise to become acquainted 
with its nature and cause. It was an immense fissure of more 
than 100 feet in width, and of a depth varying from 100 to 300 
feet. Atthe place from which we examined it, it had no other 
opening but the small loophole of which I have spoken ; but 
farther on it corresponded to a large crevice, open near the 
right bank, by which the light entered, and the intermediate 
roof, by tempering the reflection of the snow walls, gave them 
an indescribable mildness and beauty. The sides of these ca- 
verns, like immense walls of crystal, were composed of hori- 
zontal and parallel layers two or three feet in thickness, of 
a snow much hardened by pressure, but still crystalline, for 
it had not yet assumed the granular form of the névé met with 
further down. Between these layers of snow there was usu- 
ally a narrow belt of ice, but the ice was vesicular and not 
