1857. Hall, Henry. Maps show altitude profiles (by inverse fahrenheit scale for boiling of water) for two routes traversed by Gibbon, east to west, and north to south... J.A. Crew (Cape Town).
1880. Hall, Henry. Relief shown by hachures.; "Published 1st Jan. 1880."; "With additions and corrections from surveys and explorations to 1878." 40 x 69 centimeters ... Stanford (London).