Werne (1822-1874), a German adventurer, took part in the second European exploratory mission to discover the source of the White Nile, under the leadership of the Turkish officer, Selim Qaduban, which penetrated as far as Gondokoro. Werne kept a diary of valuable scientific observations and produced the first European map of the river between Khartoum and Gondokoro. Reputed to have been utilised by Burton, Speke, and Baker.

First English edition; 2 volumes in 1, 8vo (20.5 x 13.5 cm); folding plate (light foxing), folding map; original blind-stamped pebble-grained green cloth gilt, text a little shaken, a very good example; ix, 354; vi, 346pp.