Joseph Wolf became the preferred illustrator for this explorer who  had an obsession with discovering the sources of the Nile River
Joseph Wolf Joseph Wolf (21 January 1820 – 20 April 1899) was a German artist who specialized in natural history illustration. He moved to the British Museum in 1848 and became the preferred illustrator for explorers and naturalists including David Livingstone, Alfred Russel Wallace and Henry Walter Bates. Wolf depicted animals accurately in lifelike postures and is considered one of the great pioneers of wildlife art. Sir Edwin Landseer thought him "...without exception, the best all-round animal artist who ever lived"'.
Karl Mauch Karl Gottlieb Mauch (7 May 1837 – 4 April 1875) was a German explorer and geographer of Africa. He reported on the archaeological ruins of Great Zimbabwe in 1871 during his search for the biblical land of Ophir.