The first of the ice-cap was a stretch of some fifteen miles of ice, formed into enormous dome-shaped masses. They toiled up one side but travelled easily down the other, and so on, up and down, until they had attained an altitude of nearly 9000 feet above the sea-level, when they found that they were on a vast expanse of snow. The white unbroken surface stretched away as far as the eye could reach, unbroken by a ridge or rise, everywhere flat, white and immense. This was the great ice-cap, the frozen covering of the interior of Greenland, the unknown region where no man had yet set foot. But it was a mistake to term it an ice-cap. They found it to be rather a desert, a Sahara with dry drifting snow instead of the dry burning sand. And, like Sahara, it had its days of storm, when the snow whirled in clouds just as the sand rises before the scorching blast of the simoom. Very wonderful was the first experience of this Greenland dust-storm. The sky overhead was filled with dull grey clouds, heavy and opaque, and the gloom spread all around, so that whichever way one looked there was the same impenetrable veil of grey gloomy haze. The snow lost its dazzling whiteness and took instead the tint of the gloom of the surrounding atmosphere. Then the wind came, at first in fitful gusts but later growing into a steady blow, the opening squalls lifting the dry surface snow and whirling it up in the air. The steady breeze caught it and carried it along in a constantly moving stream some two feet deep, and it was then that the effect of the storm was most pronounced. The drifting particles of snow made a curious rustling noise as they moved, and as they whirled round the travellers' legs the feet were hidden beneath the dense moving veil. As a result, it was as though one were walking on nothing and going nowhere, for the grey gloom all around made one unconscious of either direction or space, and the moving snow prevented one seeing the feet or realising that there was anything solid under them. The steady hum of the drifting snow, together with its movement, made the brain dizzy, and the two explorers generally found it necessary to form a camp when such a storm came on, the snow soon piling up against their shelter tent and effectually protecting them from the wind. Then, when the breeze had died away and the snow ceased moving, they were able to dig out their sledge and proceed.