Unfortunately for his theory, the lines of stratification constantly
occur in glaciers where no such ice-falls are found. His principal
observations upon this subject were made on the Glacier du Geant, where
the ice-cascade is very remarkable. The lines may perhaps be rendered
more distinct on the Glacier du Geant by the cascade, and necessarily
must be so, if the rents coincide with the limit at which the annual
snow-line is nearly straight across the glacier. In the region of the
Aar glacier, however, where my own investigations were made, all the
tributaries entering into the larger glacier are ribbed across in this
way, and most of them join the main trunk over uniform slopes, without
the slightest cascade.
It must be remembered that these surface-phenomena of the glacier are
not to be seen at all times, nor under all conditions. During the first
year of my sojourn on the glacier of the Aar, I was not aware that the
stratification of its tributaries was so universal as I afterward found
it to be; the primitive lines of the strata are often so far erased that
they are not perceptible, except under the most favorable circumstances.
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