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. Kevimâ, 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. Kevimâ indicated one spot in the southern range of remarkable interest, associated with an incident which forms an epoch in the records of Martial geography. A sloping plateau, some 19,000 feet above the sea-level, is defined with remarkable clearness in the direction from which we viewed it. The forests appeared to hide, though they do not of course actually approach, its lower edge. On one side and to the rear it is shut in by precipices so abrupt that the snow fails to cling to them, while on the remaining side it is separated by a deep, wide cleft from the western portion of the range. Here for centuries were visible the relics of an exploring party, which reached this plateau and never returned. Attempts have, since the steering of balloons has become an accomplished fact, been made to reach the point, but without success, and those who have approached nearest have failed to find any of the long-visible remains of an expedition which perished four or five thousand years ago. Kevimâ thought it probable that the metallic poles even then employed for tents and for climbing purposes might still be intact; but if so, they were certainly buried in the snow, and Esmo believed it more likely that even these had perished.