DR. HEINRICH BARTH, a native of Hamburg, and lecturer at the University of Berlin upon geography, had already had some experience of African travel, when, in 1849, he learned that Mr. James Richardson had planned an expedition from London to Central Africa, with the view of opening up the Soudan to European commerce, and substituting for the cruel slave-trade the legitimate enterprise of working the natural riches of the country. Dr. Barth obtained permission to accompany it, and with another volunteer, also a German, named Overweg, he repaired to head-quarters. The expedition was authorized and supported by the British Government. It met, therefore, with no preliminary difficulties; and we may begin our summary of its adventures at Tripoli, whence it started for the south on the 24th of March, 1850. Entering the Fezzan, it crossed the rocky and elevated plateau known as the Hammada, and through fertile wadys, or valley-basins, separated by precipitous ridges and broad wastes of sand, made its way to Mourzouk, the capital, situated in a sandy plain, where agricultural labour is possible only under the shelter of the date-palms. The town has no rich merchants, and is not so much a commercial depôt as a place of transit. For Dr. Barth and his companions it was, however, the first stage of their journey, and, indeed, their true point of departure. They made all haste, therefore, to leave it, and on the 13th of June entered upon their great undertaking. On the 25th, after an unavoidable delay, they quitted Tasua, crossed a considerable mass of sand-hills, and descended into a more agreeable district, where the heights were crowned by tamarisk trees, each height standing alone and isolated, like sentinels along the front of an army. This pleasant variety of scenery did not last long, however; they came again upon a soil as rocky as that of the Hammada, and met with an alternation of green valleys and sterile promontories, similar to that which they had explored before they reached Mourzouk.