branch of the Gaboon, and to the Fernao Vaz.

The Ogobe is the only river between the Niger and the Congo which
escapes, through favouring depressions, from the highlands
flanking the great watery plateau of Inner Africa. By its plainly
marked double seasons of flood at the equinoxes, and by the time
of its low water, we prove that it drains the belt of calms, and
the region immediately upon the equator. The explorations of
Lieutenant Serval and others, in "Le Pionnier" river-steamer,
give it an average breadth of 8,200 feet, though broken by sand-
banks and islands; the depth in the main channel, which at times
is narrow and difficult to find, averages between sixteen and
forty-eight feet; and, in the dry season of 1862, the vessel ran
up sixty English miles.

Before M. du Chaillu's expeditions, "the rivers known to
Europeans," he tells us in his Preface ("First Journey," p. iv.),
"as the Nazareth, Mexias, and Fernam Vaz, were supposed to be
three distinct streams." In 1817 Bowdich identified the "Ogoowai"
with the Congo, and the Rev. Mr. Wilson (p. 284) shows us the
small amount of knowledge that existed even amongst experts, five
years before the "Gorilla book" appeared. "From Cape Lopez, where
the Nazareth debouches, there is a narrow lagoon running along
the sea-coast, and very near to it, all the way to Mayumba. This
lagoon is much traversed by boats and canoes, and, when the
slave-trade was in vigorous operation, it afforded the Portuguese
traders great facilities for eluding the vigilance of British
cruizers, by shifting their slaves from point to point, and
embarking them, according to a preconcerted plan."