instruments for
scientific observation. "Take your departure in whatever direction
you like," said he, "and I will take mine at an angle of not less
than fifteen degrees from it. If I am not back in three days, you may
conclude something has happened."

It was certainly very hot. Freeman had been accustomed to torrid suns in
the Isthmus; but this was a sun indefinitely multiplied by reflections
from the dusty surface underfoot. Nor was it the fine, ethereal fire of
the Sahara: the atmosphere was dead and heavy; for the rider was already
far below the level of the Pacific, whose cool blue waves rolled and
rippled many leagues to the westward, as, aeons ago, they had rolled
and rippled here. There was not a breath of air. Freeman could hear his
heart beat, and the veins in his temples and wrists throbbed. The sweat
rose on the surface of his body, but without cooling it. The pony which
he bestrode, a bony and sinewy beast of the toughest description, trod
onwards doggedly, but with little animation. Freeman had no desire to
push him. Were the little animal to overdo itself, nothing in the future
could be more certain than that his master would never see the Trednoke
ranch again. It seemed unusually hot, even for that region.

There was little in the way of outward incident to relieve the monotony
of the journey. Now and then a short, thick rattlesnake, with horns on
its ugly head, wriggled out of his path. Now and then his horse's hoof
almost trod upon a hideous, flat lizard, also horned. Here and there the
uncouth projections of a cactus pushed upwards out of the dust; some
of these the mustang nibbled at, for the sake of their juice. Freeman
wondered where the juice came from. The floor of the desert seemed for
the most part level, though there was a gradual dip towards the east
and northeast, and occasionally mounds and ridges of wind-swept dust,
sometimes upwards of fifty feet in height, broke the uniformity. The
soil was largely composed of powdered feldspar; but there were also
tracts of gravel shingle, of yellow loam, and of alkaline dust. In some
places there appeared a salt efflorescence, sprouting up in a sort of
ghastly vegetation, as if death itself had acquired a sinister life.
Elsewhere, the ground quaked and yielded underfoot, and it became
necessary to make detours to avoid these arid bogs. Once or twice, too,
Freeman turned aside lest he should trample upon some dry bones that
protruded in his path,--bon