When I undertook this work in 1863 no information could be obtained as to what was beyond our colonial frontier, except that a great part was desert land uninhabited, except in parts by wild Bushmen, and the remaining region beyond by lawless tribes of natives. I at once saw there was a great field open for explorations, and I undertook that duty in that year, being strongly impressed with the importance, that eventually it would become (connected as it is with our South African possessions) of the highest value, if in our hands, for the preservation of our African colonies, the extension of our trade, and a great field for civilising and Christianising the native races, as also for emigration, which would lead to most important results, in opening up the great high road to Central Africa, thereby securing to the Cape Colony and Natal a vast increase of trade and an immense opening for the disposal of British merchandise that would otherwise flow into other channels through foreign ports; and, at the same time, knowing how closely connected native territories were to our border, which must affect politically and socially the different nationalities that are so widely spread over all the southern portion of Africa. With these advantages to be attained, it was necessary that some step should be taken to explore these regions, open up the country, and correctly delineate its physical features, and, if time permitted, its geological formation also, and other information that could be collected from time to time as I proceeded on my work. Such a vast extent of country, containing 2,000,000 square miles, cannot be thoroughly explored single-handed under many years' labour, neither can so extensive an area be properly or intelligibly described as a whole. I have, therefore, in the first place, before entering upon general subjects, deemed it advisable to describe the several river systems and their basins in connection with the watersheds, as it will greatly facilitate and make more explicit the description given as to the locality of native territories that occupy this interesting and valuable portion of the African continent, in relation to our South African colonies. And, secondly, to describe separately each native state, the latitude and longitude of places, distances, and altitudes above sea-level, including those subjects above referred to. All this may be considered dry reading. I have therefore introduced many incidents that occurred during my travels through the country from time to time. To have enlarged on personal events, such as hunting expeditions, which were of daily occurrence, would have extended this work to an unusual length, therefore I have taken extracts from my journals to make the book, I trust, more interesting, and at the same time make physical geography a pleasant study to the young, who may wish to make themselves acquainted with every part of the globe. This is the first and most important duty