Roughly speaking, the British Protectorate, to which we have been referring, comprises the basin of Lake Nyasa and its outlet, the Shiré. This general statement, of course, requires some qualification. The north end of the lake (the British boundary is the Songwe River, running out in about 10° of S. latitude) and nearly half the eastern side are German; south of that, _i.e._ from 11° 30´ S. to Fort Maguire, is Portuguese. From Fort Maguire, the border-line runs south-east to the small lake called Chiuta, then south, by the salt lake Chilwa and Mlanje Mountain to the Ruo. The western frontier of the Protectorate is an irregular line, following more or less the watershed between the streams that flow into the lake and those that flow into the Luangwa (a tributary of the Zambezi which, unlike most tributaries, goes up-stream to join its river—in this case in a south-westerly direction), and meeting the Portuguese border about 14° S. Thence it keeps on to the south-east, as far as the point on the Shiré already mentioned, where the notice-board is affixed to the tree. Measurements in square miles convey little or nothing to my mind, as a rule, and I shall abstain as far as possible from inflicting them on the reader; but it may as well be noted here that the area of the Protectorate is estimated at 40,980. West of the territory thus defined, and between the Zambezi and the upper waters of the Congo, lies a vast region known officially as North-east Rhodesia, and reaching up to the south end of Lake Tanganika. We shall have something to say about the tribes living in this part of the country; some of them, indeed, are identical with those in the Protectorate proper; but it is with the latter that we shall chiefly have to do. We have seen that British Central Africa is a land of lakes and rivers; it is a land of mountains also. ‘Before the discovery of Lake Ng’ami and the well-watered country in which the Makololo dwell,’ said Livingstone, ‘the idea prevailed that a large part of the interior of Africa consisted of sandy deserts into which rivers ran and were lost.’ His great journey of 1852-56 dispelled this idea, and ‘the peculiar form of the continent was then ascertained to be an elevated plateau, somewhat depressed in the centre, and with fissures in the sides by which the rivers escaped to the sea.’ The great lakes all lie on this central plateau, and the rivers which drain them to the sea escape over its edge in the cataracts which for so many centuries, by interrupting navigation, have prevented the exploration of the interior. The Zambezi first throws itself into a huge crack in the earth in the Victoria Falls, and afterwards, between Zumbo and Tete, come the Kebrabasa Rapids.