ed to it, from the reed-supported orange-like _alva_ of the
lowlands to the tall _astyra_, above which stretched the timber
forests extending as high as trees could grow, while between these and
the permanent snow-line lay the yellowish herbage of extensive
pastures. A similar mountain range on earth would have presented a
greater variety of colouring and scenery, the total absence of
glaciers, even in the highest valleys, creating a notable difference.
The truth is that the snows of Mars are nowhere deep, and melt in the
summer to such an extent that that constant increase whose downward
tendency feeds Terrestrial glaciers cannot take place. Probably the
thin atmosphere above the snow-line can hold but little watery vapour.
Esmo was of opinion that the snow on the highest steeps, even on a
level plateau, was never more than two feet in depth; and in more than
one case a wind-swept peak or pinnacle was kept almost clear, and
presented in its grey, green, or vermilion rocks a striking contrast
to the masses of creamy white around it. This may explain the very
rapid diminution of the polar ice-caps in the summer of either, but
especially of the Southern hemisphere; and also the occasional
appearance of large dark spots in their midst, where the shallow snow
has probably been swept away by the rare storms of this planet from an
extensive land surface. It is supposed that no inconsiderable part of
the ice and snow immediately surrounding the poles covers land; but,
though balloon parties have of late occasionally reached the poles,
they have never ventured to remain there long enough to disembark and
ascertain the fact.

Towards evening the stream turned more decidedly to the north, and at
this point Esmo brought out an instrument constructed somewhat on the
principle of a sextant or quadrant, but without the mirror, by which
we were enabled to take reliable measures of the angles. By a process
which at that time I did not accurately follow, and which I had not
subsequently the means of verifying, the distance as well as the angle
subtended by the height was obtained. Kevima, after working out his
father's figures, informed me that the highest peak in view--the
highest in Mars--was not less than 44,000 feet. No Martial balloonist,
much less any Martial mountain-climber, has ever, save once, reached a
greater height than 16,000 feet--the air at the sea-level being
scarcely more dense than ours at 10,000 feet. Kevima indicate