First Edition, with 68 maps, plans and sections (of which 40 are double-page and many are coloured), and numerous text illustrations, tables and graphs, 4to., pp. viii, 507, contemporary half-morocco, gilt, with raised bands and marbled boards and end-papers, t.e.g., some light foxing in the text."The author, a French engineer employed by the Egyptian Government, was posted to the Sudan in 1876 as chief engineer of the Sudan. This pioneering work is a landmark in the writings on the hydrography of the Nile, and won a prize of the Geographical Society of Paris in 1892. In particular, it provided the first fully detailed chartings of the Nile cataracts. Hill pp. 76 and 153."