CASATI, GAETANO (1838-1902), Italian geographer and traveller in Africa. Born at Lesmo, he entered the corps of Ber saglieri in 1859 and took part in the wars of independence against Austria. Subsequently he was employed in the making of the ordnance survey maps of Italy. In 1879 Casati resigned his com mission to devote himself wholly to geographical work. In the same year he started for the Bahr el Ghazal province of the Sudan to join Gessi Pasha (see SUDAN : History). He travelled widely in that region and visited the upper Welle basin of the Congo. He also carried on operations against slave raiders and on the rise of the IVlandi made his way south to Lado, where in 1883 he joined Emin Pasha, under whom he served. He was for some time Emin's agent in Unyoro. There he was made prisoner and tied naked to a tree. Left to his fate he managed to escape and re joined Emin. In 1889 he accompanied H. M. Stanley and Emin to Bagamoyo and returned to Italy. Later he published an account of his travels (Eng. trans. Ten Years in Equatoria), which had added a good deal to the knowledge of the headwaters of the Nile.