ward in the _neve_ region, and toward
the lower end the upper portion takes the lead, and advances more
rapidly than the lower.

[Illustration]

I presented these results for the first time in two letters, dated
October 9th, 1842, which were published in a German periodical, the
Jahrbuch of Leonhard and Bronn. The last three wood-cuts introduced
above, the transverse and longitudinal sections of the glacier as well
as that representing the concentric lines of stratification on the
surface, are the identical ones contained in those communications. These
papers seem to have been overlooked by contemporary investigators, and I
may be permitted to translate here a passage from one of them, since it
sums up the results of the inequality of motion throughout the glacier
and its influence on the primitive stratification of the mass in as few
words and as correctly as I could give them to-day, twenty years
later:--"Combining these views, it appears that the glacier may be
represented as composed of concentric shells which arise from the
parallel strata of the upper region by the following process. The
primitively regular strata advance into gradually narrower and deeper
valleys, in consequence of which the margins are raised, while the
middle is bent not only downward, but, from its more rapid motion,
forward also, so that they assume a trough-like form in the interior of
the mass. Lower down, the glacier is worn by the surrounding air, and
assumes the peculiar form characteristic of its lower course." The last
clause alludes to another series of facts, which we shall examine in a
future article, when we shall see that the heat of the walls in the
lower part of its course melts the sides of the glacier, so that,
instead of following the trough-like shape of the valley, it becomes
convex, arching upward in the centre and sinking at the margins.

I have dwelt thus long, and perhaps my readers may think tediously, upon
this part of my subject, because the stratification of the glacier has
been constantly questioned by the more recent investigators of glacial
phenomena, and has indeed been set aside as an exploded theory. They
consider the lines of stratification, the dirt-bands, and the seams of
ice alternating with the more porous snow, as disconnected
surface-phenomena, while I believe them all to be intimately connected
together as primary essential features of the original mass.

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