An English explorer of Africa, John Hanning Speke (1827-1864) solved the riddle of the Nile River by discovering its source during the course of an epic journey to and through the Great Lakes region of eastern Africa.

Ever since the time of Herodotus, men had sought and speculated about the fountains--the ultimate origins--of the river that provided Egypt's life-blood and sustained classical as well as modern civilizations throughout much of its length. Ptolemy had hinted at the Nile's beginning in equatorial Africa, but only the 19th-century search for the sources of the main, or White, Nile (in the late 18th century James Bruce had seen the Blue Nile flow from Lake Tana in Ethiopia) produced John Speke's confirmation.

John Speke was born at Jordans, Somersetshire, on May 4, 1827. He joined the Indian army in 1844 and saw considerable action in the Punjab campaign. He liked to fight but was bored...