The commercial activity of the oases of Borkou is far from negligible; they export towards the south salt, soda, and dates, and receive in exchange cereals, butter, cattle, and smoke-dried meat. Caravans of two hundred camels may often be seen coming to load up with salt at the Arouelli salt-pits near Ounianga; and Arab caravans pass by on the way from Cyrenaica, by Koufra and Sarra wells, importing to Wadai stuffs, sugar, coffee, tea, mercery, and (in time past) arms and ammunition; and exporting principally millet, butter, smoked meat, hides raw or tanned, ostrich feathers, elephants’ tusks, and so forth. The slave-trade, formerly carried on through Borkou between Wadai and Cyrenaica on a great scale, has almost entirely ceased since we took possession of the country. =5. Exploration of the Western Borders of the Libyan Desert: Ounianga- Erdi= After drawing up the map of the western part of Borkou, subsequent to my reconnaissance in March and April of the various oases that succeed one another between Faya and Ain Galakka on the south and Gouro on the north, I devoted the last quarter of 1914 to an exploration of the unknown regions situated further east. Over and above their geographical interest, the said regions were of great military importance. My object was, in fact, to ascertain whether a counter-attack by the Senoussists, starting from Koufra and crossing the Libyan desert, could easily hope to escape the vigilance of our camel-corps patrols and fall on the remoter borders of Borkou and Ennedi. _From Faya to Ounianga._—With this intention I left the oasis of Faya on 1 October 1914, at the head of a small escort, taking with me only some thirty lean camels tired and mangy, only capable of short stages and of carrying light loads. The result was that I spent nine days in covering the 117 miles between Faya and Ounianga, a journey that offers no difficulties and is usually completed in five or six stages. The points at which water may be found are frequent—at least one every 20 miles—and permanent; but grazing-grounds were almost non-existent at that time in consequence of the eleven years’ drought the country had just suffered from. The rain that had fallen in August had, it is true, made a few green blades spring here and there, and they were eagerly snapped up by our camels as they passed; but they were still so scattered among the broken rocks that they rather emphasized than diminished the desolate barrenness of these dreary solitudes. From place to place, round a water-hole, one found a few wretched acacias, bushes of _rtem_ or tufts of _akrech_. By chance one would come across what had once been a field of dried-up _hâd_ whose thorny branches were grey with dust; but in a general way the landscape was disappointingly bare, and I wondered anxiously how long my camels would hold out on this starvation diet.