Henry Morton Stanley's first trans-Africa exploration for and successfully found the missionary and explorer Livingstone, greeting him with the famous (though disputed) words: “Dr. Livingstone, I presume?” Stanley's journey had four principal aims, to: There was controversy among earlier explorers as to whether these lakes and rivers were connected to each other and the Nile. Richard Burton thought that Lake Victoria might have a southern inlet, possibly from Lake Albert, meaning that the source of the Nile was not Lake Victoria as Speke had argued. Samuel Baker thought that Lake Albert might have an inlet from Lake Tanganyika. Livingstone thought that Lualaba was the source of
John Hanning Speke tried to remove it with a knife. Unable to rent the larger vessel from the Arab, Speke returned. The pair were unable to explore Lake Tanganyika properly and they initially misunderstood that a river flowed out of it from the north side. A few weeks later Sidi Mubarak Bombay confirmed via locals that the river flowed into the lake; however, since neither man actually saw this river, this remained a source of speculation. They had also heard of a second lake to the north-east, and in May 1858, they decided to explore it on the way back to the coast.