_Oued_ is the Arabic word for river, and, when applied to a village or locality, presupposes the presence of a stream. I saw nothing about El Oued which even remotely suggested the proximity of water, however, until, climbing one morning to the summit of the range of sand-dunes which encircled the camp, I looked down upon a dozen acres or so of as prosperous looking a fruit-orchard as I have ever seen. I rubbed my eyes incredulously, so astonishing was it to see this patch of brilliant green set down in the heart of that arid, sun-scorched, apparently hopeless waste. Yet there it was, with its ordered rows of fruit-trees—pears, apples, peaches, apricots, figs, pomegranates—in full blossom; its long trellises of grapes, the stems of the vines as large as a man’s wrist; its ranks of towering date-palms with their huge clusters of rapidly ripening fruit; and, in the heart of it all, a really charming little bungalow embowered in flowers and vines. The place was, I learned, the property of a prosperous and progressive Arab, who had obtained an unlimited supply of pure water by sinking a number of artesian wells to a depth of not much over a hundred feet. El Oued was appropriately named after all, it seemed, for the river was there, even though it was below the surface. But the anxieties of a Saharan husbandman are not ended once he has obtained an adequate and assured supply of water, for he must still guard his hard-won area of fertility against the stealthy encroachments of the shifting sands, which can be held at bay only by maintaining along the edge of the oasis a sand-break composed of certain trees, shrubs, and grasses. And, if prosperity is to be maintained, that barrier must be guarded as vigilantly as a Hollander guards his dikes. For the desert, like the sea, never becomes discouraged, never gives in; you can never say that you have conquered it. It can be held in check only by unceasing vigilance. [Illustration: THE SHRINE IN THE SANDS Si Sayah Laroussi, Grand Marabout of the Tidjania, welcomes us to his palace in Guemar Caïds of the Tidjania in the courtyard of the mosque at Guemar]