Mapping the Niger, 1798-1832: Trust, testimony and 'ocular demonstration' in the late enlightenment
This paper is about the role of trust, testimony and direct observation in the making of maps and about the ways in which these issues were apparent in the mapping of the Niger River. By the late eighteenth century, the Niger River was a two-thousand-year-old geographical problem. Although classical writers, Arab geographers and French authorities had produced maps of the river, its direction of flow was not confirmed by direct observation until 1796 when the explorer Mungo Park did so. Yet Park solved only one part of the problem, and he died in 1805 while attempting to solve the remaining question: where did the river end? This question was not answered by direct observation until 1830. By then, however, the 'Niger problem' had been resolved, and the solution mapped, by two early nineteenth-century geographers who had charted the river's course without travelling to Africa. Attention is also paid to the maps that first presented the Niger's termination on the basis of field observation. What all this evidence raises is the question of trust in others' testimony and the role of travel and direct observation in the production of maps as 'truthful' documents in the late Enlightenment.