had just covered 350 miles on foot in fourteen days in conditions of the utmost hardship, had forgotten their weariness and were contemplating with respect, on the lieutenant’s table, the “good little iron” that had saved them from the most horrible death. As for the guide, he was left unmolested, his criminal intention not being susceptible of absolute proof. It was the wisest course to take, for by punishing him without proofs, all we should have gained would have been to terrify men whom we might need later on! In the desert, the best guides may have their weak moments! _From Tekro to Ounianga._—From Tekro I came back to Ounianga, and continuing eastwards by the lakes of Little Ounianga and N’Tegdey I reached the salt-pits of Dimi, after crossing a chain of little sand- dunes about 50 feet high, stretching from north-east to south-west, and extending from 5 to 6 miles in breadth. This salt-pit lies in a sort of huge circle of rock, in the middle of which rises an isolated conical peak 500 or 600 feet high. It seems to me more extensive than that of Arouelli, but the salt from it does not seem to be so much in demand, on account of the very large proportion of sand it contains. The result is that it is hardly used by any one except the natives of Ennedi, who have only three days’ journey to go in order to get a supply of it. The grazing, though by no means abundant, was less scanty than in the regions I had just come through, and my skeleton-like camels could eat their fill, for the first time in a whole month. From the top of the rocks of Dimi my Ounia guide, Sougou, pointed out to me in the east the almost horizontal lines of cliffs forming the most westerly point of the mysterious plateaux of Erdi. The word “Erdi” means in the language of the Toubous “expedition, razzia,” and would appear to have been applied to that region from time immemorial because it served as a meeting-place for the bands of raiders who put the caravans to ransom and pushed their raids as far as northern Dar Four and Kordofan, and sometimes even to the valley of the Nile in its middle reaches. According to the guide, rocky tablelands were to be found there, of an altitude comparable with that of Ennedi; the rains were less rare than in Borkou, the grazing-grounds for camels abundant, and the points where water could be found were hidden away in gorges difficult of access, little known, and hard to find the way to. For his own part, he hardly knew any except those of Erdi-Dji and Erdi-Ma, separated by a distance of 70 or 80 miles.