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
Jakob Erhardt then in the "Church Missionary intelligencer" in 1856. The map was reproduced with commentary in other publications. The reports of snow on mounts Kilimanjaro and Kenya, near to the equator, caused considerable controversy. The map caused the British government and the Royal Geographical Society to hire Richard Francis Burton and John Hanning Speke to investigate the great lake, or lakes, and determine if they were the source of the Nile. The map came to be known as the "slug map" from the shape of the Uniamesi or Niassa inland sea. Burton called it the Mombas Mission Map. Erhardt worked in