In the _neve_ fields, where the strata are still horizontal, the few
blue bands observed are perpendicular to the strata of snow, and
therefore also perpendicular to the blue seams of ice and the sheets of
dust alternating with them. Upon the sides of the glacier they are more
or less parallel to the slopes of the valley; along the line of junction
of two glaciers they follow the vertical trend of the axis of the mass;
while at intermediate positions they are more or less oblique. Along the
outcropping edges of the strata, on the surface of the glacier, they
follow more or less the dip of the strata themselves; that is to say,
they are more or less parallel with the dirt-bands. In conclusion, I
would recommend future investigators to examine the glaciers, with
reference to the distribution of the blue bands, after heavy rains and
during foggy days, when the surface is freed from the loose materials
and decomposed fragments of ice resulting from the prolonged action of
the sun.
* * * * *
The most important facts, then, to be considered with reference to the
motion of the glacier are as follows.
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