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,
George Speke brother, William, was descended the explorer John Hanning Speke George Speke George Speke (1623–1689) was an English politician. A Royalist during the English Civil War, after the Restoration (England) he became an early Whig supporter in Parliament. Speke was from Whitelackington, near Ilminster in Somerset; his parents were George Speke, and Joan, daughter of Sir John Portman. He became a ward of Sir Robert Pye, and later married his daughter. Speke gave financial support to Prince Rupert at Bridgwater; and when the town surrendered to Thomas Fairfax in July 1645 he was taken as a hostage and his goods sequestrated.