The Narrative of an Explorer in

Tropical South Africa

London: John Murray, 1853

This is Galton's account of his expedition in the early 1850s to then relatively uncharted South-West Africa, which won him a Gold Medal from the Royal Geographical Society and launched his scientific career.  It remains extremely interesting today, written in a fresh and engaging style, with keen observation of the peoples he encountered, and some fine humour.

Galton financed the expedition himself, but was accompanied by Charles John Andersson.  Originally he had intended to reach Lake Ngami (recently discovered in Bechuanaland by David Livingstone) from the Cape, but reports of hostile Boer settlers forced him to change his plans; instead he landed at Walfisch (Walvis) Bay and journeyed through the interior of what later became South-West Africa, and then Namibia, to Ovamboland and back.

This was Galton's first major work, and it went through several printings and two editions.  The second edition was issued in 1889 as part of the Minerva Library of Famous Books, with a new appendix covering more recent knowledge of the territory.

Charles John Andersson also wrote an account of his travels with Galton, and by himself, and published it under the title: LAKE NGAMI.

I have read both Galton's and Andersson's narratives, and LAKE NGAMI is far more enjoyable.