on the trail again, to start the dumbly protesting animals on the thirty-six-hour drive to the next unfailing water, against the instinct which bade them stay. A valley of delight it was, a jewel, verdant and peaceful, forced by man to serve a vicious purpose; but as if in punishment for its perversion the glistening sand hills crept slowly nearer, each receding tide of their slow advance encroaching more and more each year until now the valley had shrunk by half and a stealthy grayness crept insiduously into its velvety freshness like the mark of sin across a harlot's cheek.
Near the fenced-in spring was an adobe building, deserted except when a drive crew sought its shelter, and it served principally as a storehouse should a place of refuge suddenly be needed. It lay not far from the sloping banks of detritus which now ran halfway up the sheer, smooth stone walls enclosing the valley. Across from it on the southern side of the depressed pasture a broad trail slanted up the rock cliffs to the desert above. The cabin, the trail, and the valley itself long ago would have been obliterated by sand but for the miles of rocks, large and small, which lay around it like a great, flat collar. Should some terrific sand storm sweep over it with a momentum great enough to bridge the rocky floor the valley would cease to be; and smaller storms raging far out on the encircling desert carried their sands farther and farther across the stubborn rock, until now its outer edge was closer by miles. Already each rushing wind retained sand enough to drop it into the valley and powder everything.
The pock-marked guide, disdaining the precarious labors of getting the herd down the ledge with no fatali-
