It would appear, from the proceedings of the Berlin Academy of
Sciences, that Dr Güssfeldt’s explorations in the central Chilian
Argentine Andes extended from November 1882 to March 1883, in the wild
and lofty mountain region containing Aconcagua, the most elevated
known point of the American continent, which lies between thirty-two
and thirty-five degrees south latitude, and is bounded on the east by
the Argentine Pampas, and on the west by the Pacific. Much of this
journey being through new country, Dr Güssfeldt daily observed the
great orographical and landscape features, the glacial conditions
above the snow, the character of the vegetation, and the phenomena
of rock-weathering. He also undertook the special duty of fixing
positions astronomically and taking altitudes; for which purpose he
was provided with nineteen instruments. The central Chilian Argentine
Andes are sketched by the traveller as two parallel chains, having on
the Pacific an outlying coast-range. The western chain is the true
water-parting of the Atlantic and Pacific; and the eastern is in many
places broken through by the waters rising in the great trough between
the two chains, which has no well-defined valley formation, indications
of a longitudinal depression being only found at intervals, constantly
interrupted by cross ridges. This trough or basin, one hundred and
eighty-five miles in length, is very difficult of exploration, and only
three months of the year are available for the purpose. The doctor
crossed the divide at four points, and obtained altitudes from nine
thousand four hundred and ninety-four feet to twenty-two thousand
eight hundred and sixty-seven feet, which was reached near the great
volcano Aconcagua, not far from the commencement of Valle Hermoso.
A most interesting question of the effect of rarefied air at great
elevations upon the human frame is dwelt upon by the doctor. He states
that he and his assistant attained twenty-one thousand and thirty feet
on Aconcagua, and were able to work their scientific instruments at
that height, though not in good condition, through anxiety and want of
sleep. Their lungs were physically exhausted by the effort of speaking;
but there was no flow of blood from nose or ears. He says that the
so-called _puna_ can be resisted by mental effort and confidence,
the only effect upon a properly trained individual being increased
lung-action, and that any one who could work as he did at twenty-one
thousand and thirty feet, could reach the top of Aconcagua, where the
proportion of oxygen is only 6.2-3 per cent. less than at the former
elevation.