The death-dealing hardships to the slaves were for the most part endured on the long journey to Cairo, or, when the trade was suppressed there, to points north of the Sudan, such as Tripoli, or certain ports on the Red Sea. Those who were hardy enough to reach the slave-markets were usually well treated by their Muhammedan masters. During the time of Baker Pasha's administration, while he was pursuing the slave-traders and establishing Egyptian outposts, the whole course of the Nile from the Great Lakes became well known to the civilised world, though after this period Baker Pasha did not make any further voyages of discovery into unknown parts. During the years of 1859 and 1860, an adventurous Dutch lady of fortune, Miss Alexandrine Tinne, journeyed up the Nile as far as Gondokoro, and in 1861 she commenced to organise a daring expedition to find the source of the Bahr-el-Ghazel, and explore the territory between the Nile basin and Lake Chad. She started from Khartum, and ascended the Bahr-el-Ghazel as far as the affluent Bahr-el-Hamad. She then crossed overland as far as the Jur and Kosango Rivers, and reached the mountains on the outlying districts of the Nyam-Nyam country. Here the members of the expedition suffered from black-water fever, and only with the greatest difficulty were they able to return to Khartum, where they arrived in July, 1864. In 1868 Miss Tinne, nothing-daunted, started for Lake Chad from Tripoli, with the intention of closing in upon the Nile from the eastern sources of the affluents of the Bahr-el-Ghazel. On reaching Wadi-Aberjong, however, this brave-hearted woman was waylaid by the fierce Tuaregs, and was beheaded August 1, 1868. In the sixties, Georg Schweinfurth, a native of Riga, in the Baltic provinces of Russia, set out to explore Nubia, Upper Egypt, and Abyssinia for botanical purposes. Subsequently the Royal Academy of Science in Berlin equipped him for an expedition to explore the region of the Bahr-el-Ghazel. He entered the Sudan by Suakin on the Red Sea, and crossed the desert to Berber, reaching Khartum on November 1, 1868. The following January he set out along the course of the White Nile, passed Getina, and examined the vegetation (sudd) which had drifted down from all the affluents of the White Nile. He prolonged his stay for three years on the Bahr-el-Ghazel, solely absorbed in scientific studies, and, unlike his predecessors, he was unconcerned with reforms and attempts to suppress the slave-trade. Schweinfurth penetrated so far into the heart of Africa that he reached the Congo basin and explored the upper waters of the Welle River, and on his return to Europe he published a work, in 1873, called "The Heart of Africa." In this book he tried to demonstrate that the area of the Victoria Nyanza was taken up by a chain of five lakes.