Whether these enterprising young African explorers had reached the neighbourhood of Lake Chad, as we might be disposed to believe, or the Niger in the vicinity of the great bend of the main stream, it would be waste of time to ask. Let us be satisfied with knowing that at this very early period of the world’s history, many centuries before the Christian era, the Central or Western Sudan of our days was reached, and the fact established that through it ran a great river. In this way the exploration of Central Africa was inaugurated--the first uncertain glimmer of light thrown upon its dark surface; and the River Niger revealed to the world to be a theme of discussion to arm-chair geographers, and a goal to be aimed at by the more adventurous spirits who would realise their thoughts in deeds rather than on paper. CHAPTER II. _MORE LIGHT: THE ARAB PERIOD._ For many centuries but little was added to the knowledge of Africa acquired by the early classical writers. Carthage fell from its high estate, and on its ruins Rome, with boundless ambition and seemingly boundless powers of attainment, built for itself a new and equally magnificent African Empire. But where man could not stay the advancing tide, Nature set bounds to the force of Roman arms, and at the borders of the desert mutely said, “Thus far shalt thou go, and no further.” The Roman power rose to the zenith of its glory, and still the desert remained uncrossed; it dwindled towards its fall, and then its days of geographical conquest were over. In Northern Africa, as elsewhere, the mythological gave place to the Christian era, and the influence of the new religion spread apparently to the remotest desert tribes. It was not, however, fated to be permanent. In the seventh century a new prophet had risen in the Sacred East, and the seeds of a mighty revolution were germinating in the deserts of Arabia. The boundaries of its parent country soon proved too small for the astonishing vitalities and ardent missionary enterprise of the new faith--the faith of Islam. Bursting out, it pushed with incredible rapidity along the north of Africa, overwhelming Paganism and Christianity alike in its irresistible course, till reaching the Atlantic it turned to north and south in search of new fields to conquer for God. The natural difficulties which had stopped the southern progress of the Carthaginians and the Romans formed no barrier to a people born in a desert. In the plateau lands of the Berber tribes the Arabs were at home. Winged with a fiery enthusiasm which nothing could withstand, and inspired by a hope of heaven which nothing could shake, they swept from district to district, from tribe to tribe, everywhere carrying the blazing torch of Islam, everywhere striking fire from the roving people with whom they came in contact, till from every Saharan oasis there was heard the common cry, “There is no God but the one God.” In the new