"Local muscle employed on an 1836 journey down the River Amazon, captured in a lithograph in W. Smyth and F. Lowe's Narrative of a Journey from Lima to Para, Across the Andes and Down the Amazon."
"The navigation of rivers in British Guiana required overland transport of boats to bypass cataracts. This photograph was taken in 1878."
The research project is called Hidden Histories of Exploration from the Royal Geographical Society and Royal Holloway, University of London, funded by the AHRC.
Source: The Guardian