With regard to the time of the winds and rains in Central Africa, I have tried several times, but find myself incapable of explaining these magnificent natural phenomena. It appears certain, that the monsoons of the Indian, the trade-winds of the Atlantic Oceans, and the north winds from the Mediterranean, are subject to different natural laws in the interior of Africa, where it is comparatively cooler than on the sea-shore; for the winds were never constant during our course: they changed continually from side to side, and all the observations and calculations of our sailors, accurate as they are in other places, failed in ascertaining the tide and quarters of the moon. As to the mutual swelling of the two Niles near Khartùm (called by the Turks Khàrdùm), the sources have nothing to do with the first rising of the water, but the succeeding ones give a quantity of water to the countries subject to tropical rains, together with their gohrs and tributaries, among which the Sobàt is the most considerable for the White Stream. This mass of water immediately becomes imperceptibly level, excepting certain disproportions, with the head of Sennaar, conformably to hydrostatic laws. It would be an idle attempt to endeavour to speak out clearer and more strikingly touching the formation of the soil of Central Africa; for a master like Professor Carl Ritter has already done this in his “Glance at the Source-territory of the Nile.” In order to set aside many preconceived opinions, and again to give the true imprint of my own views, I do not hesitate to annex the report of Dr. Girard, whom I have several times mentioned, and which was contained in the above instructive little work, being partly founded upon my geognostical collection; because this learned young man has discovered and ascertained, with acuteness rarely to be found, the quality of the soil in Africa, so far as I am able to judge from my expedition. He says:—“There are three great mountain chains in the eastern part of Central Africa, one extending to the east, the other to the South, and the third to the West. The eastern one surrounds the large Tzana-lake, and contains the sources of the Tacazze and the Blue Nile, and ascends easterly from the latter to a height of more than 10,000 feet. The southern and south westerly, respecting the elevation of which nothing is known, forms the water-shed between the tributaries of the Nile and the territory of the streams flowing westerly, and is that region formerly called the Mountains of the Moon. Lastly, the north-westerly, the centre of which is in the Jebel Marra, from which some tributaries wind towards the south, to the Bah’r-el-Abiad; but the most of these subordinate streams flow towards the west, the centre of Africa. Between the eastern and southern mountain-stock, there is another chain of high mountains, not extensive but lofty, which, forming the westerly part of Enarea, appears to spread to the kingdom of Bari, and attains in Enarea a