Five Weeks in a Balloon the need to release gas or throw ballast overboard to control his altitude, allows very long trips to be taken. This voyage is meant to link together the voyages of Sir Richard Burton and John Hanning Speke in East Africa with those of Heinrich Barth in the regions of the Sahara and Chad. The trip begins in Zanzibar on the east coast, and passes across Lake Victoria, Lake Chad, Agadez, Timbuktu, Djenné and Ségou to St Louis in modern-day Senegal on the west coast. The book describes the unknown interior of Africa near modern-day Central African Republic as a desert,
John Hanning Speke variety of tropical diseases once they went inland. By 7 November 1857 they had traveled over 600 miles on foot and donkey and they reached Kazeh (Tabora), where they rested and recuperated among Arab slave traders who had a settlement there. In Kazeh Burton became gravely ill and Speke went temporarily blind as they travelled further west. After an arduous journey, the two arrived in Ujiji in February 1858 and became the first Europeans to reach Lake Tanganyika (although Speke was partially blind at this point and could not properly see the lake). They decided to explore the lake but