The stream near which we had halted afforded the last opportunity to obtain water until we should complete the long drive across the sands. Our horses were fed with fine wheat flour, the only nourishment which we could secure to stay them through the day. After having filled the water kegs and canteens from the stream, the difficult march was continued. The day was so intensely hot that nearly all members of the party walked to relieve the perspiring horses. The country we were traversing was an area of loose, dry sand. Its surface was marked by small mounds and ridges of sand, the ridges all trending in one direction and evidently drifted with the prevailing wind behind a clump of stunted grease wood, a small shrub which grows on alkaline soils and, like other desert growths, is stiff and stubby,--possibly a provision of nature to preserve its scant foliage from being browsed; shrubs so protected remained, a survival of the fittest. Some such provision is certainly necessary to protect the plant life of the desert in its struggle for existence. The surface of the sand was slightly hardened by a thin scale, possibly due to solidification in drying, after a passing shower had moistened the salts in the sand. The scale in many places prevented the wheels from sinking deeply. The wagons were, therefore, scattered along side by side, because a track once followed was deeply cut in the ruts. Numerous lizards (swifts) glided along the parched surface of the Sahara and were the only specimens of animal life that I observed there with any interest. An experience on this grease wood desert may have prompted the inquiry ascribed to one of our statesmen, who is alleged to have asked in 1843 concerning this western territory, "What do we want with the vast worthless area, this region of savages and wild beasts, of deserts of shifting sands and whirlwinds of dust, of cactus and prairie dogs?"