We could not understand why the natives called Moero much larger than Tanganyika till we saw both.  The greater Lake lies in a comparatively narrow trough, with highland on each side, which 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 Rovukwe 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 deg. 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 stems, and the people make strong striped black and white shawls of the cotton.

It was pleasant to meet the palm-oil palm (Elais Guineaensis) at Casembe’s, which is over 3000 feet above the level of the sea.  The oil is sold cheap, but no tradition exists of its introduction into the country.

I send no sketch of the country, because I have not yet passed over a sufficient surface to give a connected view of the whole watershed of this region, and I regret that I cannot recommend any of the published maps I have seen as giving even a tolerable idea of the country.  One bold constructor of maps has tacked on 200 miles to the north-west end of Lake Nyassa, a feat which no traveller has ever ventured to imitate.  Another has placed a river in the same quarter running 3000 or 4000 feet up hill, and named it