as this, it is above all things desirable to seize and book
every object worth noticing on the way out : I always
carried my note-book and pencil tied to my jacket
pocket, and generally walked with them in my band.
I t is impossible to observe too soon, or too much • if
the excursion is long, little is done on the way home •
the bodily powers being mechanically exerted, the’
mmd seeks repose, and being fevered through overexertion,
it can endure no train of thought, nor be
brought to bear on a subject.
Before leaving the Yangma valley, I measured the
deration of the great village-terrace and thatof one on
the west flank ; the former was about 400, and the
latter 700 feet above the floor of the valley.
Considering this latter as the upper terrace, and concluding
that it marks a water level, it is not very
difllcult to account for its origin. There is every
reason to suppose that the flanks of the valley were
once covered, to the height of the upper terrace, with
an accumulation of débris; though it does not follow
that the whole valley was filled to the same depth ; the
effect of glaciers being to deposit moraines between
themselves and the sides of the valley they fill ; as also
to push forward similar accumulations. Glaciers from
each valley, meeting at the fork, where their depth
would be 700 feet of ice, would both deposit the
necessary accumulation along the flanks of the valley,
and also throw a barrier across it. The melting waters’
of such glaciers would accumulate in lakes, confined by
the frozen earth, between the moraines and mountains.
Such lakes, on a small- scale, are found at the terminations
and sides of existing glaciers, and are
surrounded by terraces of gravel and small stones;
these terraces being laid bare by the drainage of the
lakes during seasons of unusual warmth. To explain
the phenomena of the Yangma valley, it may be
necessary to demand larger lakes and deeper accumulations
of debris than are now familiar to us, but the
proofs of glaciers having once descended to from 8000
to 10,000 feet in every Sikkim and East Nepal valley
communicating with mountains above 16,000 feet
elevation, are incontrovertible, and the glaciers must, in
some cases, have been fully forty miles long, and 500
feet in depth. The absence of any moraine, or of
blocks of rock in the valley below the fork, is I believe,
the only apparent objection to this theory; but the
magnitude of the moraines bears no fixed proportion
to that of the glacier, and at Pabuk, the steep ridges of
débris, which were heaped up 200 feet high, were far
more striking than the more usual form of moraine.
On my way up to Yangma I had rudely plotted the
valley, and selected prominent positions for improving
my plan on my return : these I now made use of,
taking bearings with the azimuth compass, and angles
by means of a pocket sextant. The result of my
running-survey of the whole valley, from 10,000 to
16,000 feet, I have given along with a sketch-map of
my routes in India, which accompanies this volume.