sea below the Sette Cama estuary. But between the Ogoway and the Congo the most important stream is the Kwilu (Nguella), which higher up is known as the Niadi or Niari, with a total course of about 360 miles. Like the Ogoway, the Kwilu describes a great bend northwards, and after its junction with the Lilli and with an emissary from the Nyanga, it pierces the region of schistose hills through
a series of abrupt defiles. It is navigable by gunboats for 36 miles from its mouth to a "gate" of vertical rocks rising 100 feet above the stream, and supposed by the natives to be kept open by a powerful fetish, who, however, may close the passage at any moment. Higher up follow still more formidable gorges, in one of which the river, from 1,000 to over 2,000 feet broad on the plains, is contracted to a narrow channel 20 feet wide. The Kwilu, which in some respects offers greater
