a n d ' along the Lukanga may be reckoned, being
offshoots of Irehn, the figures of the population may
reasonably be doubled.
On the. 23rd, we steamed up the Lukanga River,
which we took to, be a river, though in reality it was
the tail end, or the sluggish effluence of a lake. It.
appeared more like a broad and winding canal. The
shore, for a considerable distance, was a reedy fen, relieved
in places by a clump of mimosa, or by a grander
height of scrub, and finally by an isleted grove. A
few miles up, a humpy rise of reddish clay showed a
village with bananas and palms, and gardens of cassava
outside. Fishermen were numerous; canoes being seen
returning from or going to the fish-catching. From
300 yards the Lukanga opened Out to a mile in
breadth, which gradually widened further into a little
lake. We were then shown a course varying from
one to two miles wide, which we followed; the shores
looming up picturesquely in wooded banks which
might almost be called hills. The villages were becoming
more numerous. Presently, when half-way
through this arm of the lake, we turned into a narrow
channel by the village of Maboko, which was still
more narrowed by rows of stakes, sedge, water-lilies,
lotus, papyrus and other reeds. Three-quarters of an
hour later—after winding in and out a crooked watery
path—Lake Mantumba burst into view. We steamed
along the northern shore—the southern being distant
about five miles*—until at 4, p .m ., when on the south,
the shore disappeared. A t , sunset, we had reached the
MANTUMBA LAKE. 47
eastern shore, and camped on an island near Ugangi; 1883. June 23.
whither some natives visited us, and told us of the Mantumba
Watwa being many days inland, from whence they
obtained their ivory and camwood. Ten days’ steaming
into beautiful little bays and creeks, past Ibingi
and Ikoko, brought us to near Ikulu at 5 p .m ., along
the eastern shore, and round by the flat southern
shore, to a portion of the western shore. By noon of
the 25th we had steamed 144 English miles in. the
circumnavigation of the lake.
Mantumba Lake, like. Lake Leopold II., is a shallow
depression in the lowland of this portion of the Congo
i basin. The greatest depth ascertained is thirty-two
feet. Like the latter, it seems.to have been caused by
| a .sudden subsidence of the ironstone substructure,
[which, at many.places, shows the ragged sharp edges
lof fracture as clearly as though newly made. In other
■parts again the land rises into low hills, not high
■enough to attract particular notice, but clothed with
»fine forests of redwood, for which this country is noted.
■Where the ironstone crust still shows its ragged frontpage
to the view, deep cavernous recesses are seen
■underneath. Over these the stone projects like a shelf
■of rock, proving its tenacious composition, as it fre-
■quently supports trees of considerable girth and height;
■On the western shores, in some of its many baylets, the
■pebbly beach strewn with round ironstone, and quartz,
■and reddish, porous, stone pebbles, shows trace's of
■much higher water, and effects of stormy waves.
Everywhere the shore is lined by these pebbles. Some