In his book King Leopold’s Ghost, Adam Hochschild describes the stretch of the Congo River as it approaches the sea:

Much of the Congo River basin, we now know, lies on a plateau in the African interior. From the western rim of this plateau, nearly a thousand feet high, the river descends to sea level in a mere 220 miles. During this tumultuous descent, the river squeezes through narrow canyons, boils up in waves 40 feet high, and tumbles over 32 separate cataracts. So great is the drop and the volume of water that these 220 miles have as much hydroelectric potential as all the lakes and rivers of the United States combined.

The inland stretches of the river, however, are navigable, with water levels that tend not to vary. The Congo drains an area larger than India with seven thousand miles of interconnecting waterways. In the last quarter of the 19th century, as explorers considered how to open trade routes, or what might better be called plunder routes, to the Congo’s interior, they realised that if steamboats could be assembled above the rapids, timber could easily be found to burn in the boilers and power the boats; the river and its tributaries could be navigated. The river itself was a rich source of food, with five hundred different kinds of fish, and it helped that the territory which comprised the river basin was not a single kingdom with any form of centralised power which could defend itself. There were two hundred different ethnic groups with four hundred different languages and dialects. Many of these groups had been severely weakened by two centuries of the slave trade.

LRB 13 September 2012 | PDF Download