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
Samuel Baker Khartoum, leaving that city in December 1862 to follow up the course of the White Nile. Two months later at Gondokoro he met Speke and Grant, who, after discovering the source of the Nile, were following the river to Egypt. Their success made him fear that there was nothing left for his own expedition to accomplish; but the two explorers gave him information which enabled him, after separating from them, to achieve the discovery of Albert Nyanza (Lake Albert), of whose existence credible assurance had already been given to Speke and Grant. Baker first sighted the lake on 14 March