John Hanning Speke of the way. Once Speke and Burton were back on the coast they went by ship to Zanzibar and then traveled to Aden. When back at the coast Burton had written a letter to Norton Shaw of the Royal Geographical Society (which had partially sponsored the journey) in which Burton enclosed a map of Lake Victoria made by Speke and wrote "there are grave reasons for believing it (the map) to be the source of the principal feeder of the White Nile." Once in Aden, Burton was not granted a medical certificate to travel and thus Speke left on HMS
Sidi Mubarak Bombay slave in India many years and learned Hindi. He was emancipated after his owner died, and returned to Africa. In Africa, Bombay met John Hanning Speke, who asked him to join his expedition to find the source of the Nile River. Bombay and Speke communicated with each other in Hindi, as it was the only language both of them understood. Bombay was well regarded by the British explorers; in the words of Burton, "The gem of the party, however, is one Sidi Mubarak, who has taken to himself the agnomen of 'Bombay.'" Between 1856 and 1876, Bombay participated in expeditions