Into the Interior of Africa

This chapter goes inland, looking for a good measure of travel time to the nearest international slave port as a measure of societal exposure to international slave traders on the coast. It quantifies African transportation technology, accounting for the effects of ground cover (rainforest versus desert, for example), terrain (uphill or downhill), river velocity, headload, and local knowledge about the best path forward. In seeking a good measure, we visit early nineteenth-century Metropolitan Asante, where “location marked time.” We then catch passage to Europe during the Industrial Revolution, where innovation in clock technology allowed “time to mark location,” especially valuable at sea but eventually miniaturized enough to become the most valuable instrument an explorer could carry. Then, back to Africa, where we use the latest technology of the Industrial Revolution to measure travel time again. We learn how a mosaic captures history, feel the burden of headload, see how rivers unite and mountains divide, and appreciate the importance of relying on local knowledge about the best path forward. We can know all of this now thanks to modern GIS computer software.