Cyclopædia of Modern Travel ... comprising narratives of the most distinguished travelers since the beginning of this century: prepared and arranged by Bayard Taylor
1856|Taylor, Bayard.
The Yoruba Country, &c. : with the course of the Niger & Tshadda
1862|Church Missionary Society.1:6 000 000
The River Niger.
1844|Arrowsmith, John1:3 400 000
West Africa. No. II
1848|Morse, Sidney E.1:8 500 000
West Africa II.
1839|Society for the Diffusion of Useful Knowledge (Great Britain)1:5 600 000