Paris, Académie des Sciences de l'Institut de France, 1934-1935. Two parts in one. 4to (27.2 x 22.5 cm). 828 pp. [1-370, 1-458; one folded map, one coloured geological map and 32 plates (two coloured) [numbered 1-20, 1-12]. Contemporary half cloth over marbled boards. Gilt title and gilt vignettes on the spine. Original printed wrappers bound in.

Important geological, volcanological, botanical, zoological, and ethnological expedition to a then poorly explored part of northern Chad in the central Sahara. The Tibesti massif has several volcanic peaks above 3,000 meters, which make up the highest mountains of the region, and its geology, ethnography and zoology are surprisingly complex. The expedition results are especially important because of the Dalloni and Lacroix contributions on volcanology and palaeontology. The second part contains well-illustrated data on ethnography and human history. Contained in Volumes 61 and 62 of the academy's Mémoires, together with a few smaller, unrelated, mainly bibliographic papers. Very uncommon. Especially the first volume is rare. A nicely bound copy.