is always visible; but when we look at Moero, to the south of
the mountains of Rua on the west, we have nothing but an
apparently boundless sea horizon. The Luapula and Rovukwé form a
marsh at the southern extremity, and Casembe dissuaded me from
entering it, but sent a man to guide me to different points of
Moero further down. From the heights at which the southern
portions were seen, it must be from forty to sixty miles broad.
From the south end of the mountains of Rua (9° 4' south lat.) it
is thirty-three miles broad. No native ever attempts to cross
it even there. Its fisheries are of great value to the
inhabitants, and the produce is carried to great distances.

Among the vegetable products of this region, that which
interested me most was a sort of potato. It does not belong to
the solanaceous, but to the papilionaceous or pea family, and
its flowers have a delightful fragrance. It is easily propagated
by small cuttings of the root or stalk. The tuber is oblong,
like our kidney potato, and when boiled tastes exactly like our
common potato. When unripe it has a slight degree of bitterness,
and it is believed to be wholesome; a piece of the root eaten
raw is a good remedy in nausea. It is met with on the uplands
alone, and seems incapable of bearing much heat, though I kept
some of the roots without earth in a box, which was carried in
the sun almost daily for six months, without destroying their
vegetative power.

It is remarkable that in all the central regions of Africa
visited, the cotton is that known as the Pernambuco variety. It
has a long strong staple, seeds clustered together, and adherent
to each other. The bushes eight or ten feet high have woody