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
John Hanning Speke Grant reached Gondokoro in Southern Sudan, where he met Samuel Baker and his "wife". (Her name was Florence von Sass and she had been rescued by Baker from a slave market in Vidin during a hunting trip in Bulgaria.) Speke had expected to meet John Petherick and his wife Katherine at Gondokoro, as they had been sent by the RGS south along the Nile to meet Speke and Grant. However the Pethericks were not there but on a side expedition to trade ivory, as they had run out of funds for their expedition. This caused some hard feelings between Pethrick