At home Livingstone was welcomed with extraordinary enthusiasm, receiving the acknowledgments and honors of scientific societies, universities, town councils, and other public bodies in every quarter of the country. In addition to these tokens of honor, the fifteen months spent at home were signalized by three things: the writing of his book, "Missionary Travels" (1857), which was received with the liveliest interest; his visit to Cambridge, awakening the enthusiasm of many of the students, and leading to the formation afterward of the "Universities Mission;" and his appointment by Her Majesty's Government as chief of an expedition for exploring the Zambesi and its tributaries, and the regions adjacent. On this expedition Livingstone set out on March 10, 1858. While successful in many ways, it led to not a little disappointment. Livingstone explored the Zambesi, the Shiré, and the Rovuma; discovered Lakes Shirwa and Nyassa, and came to a decided conclusion that Lake Nyassa and its neighborhood was the best field for both commercial and missionary operations. His disappointments arose from the grievous defects of a steamer sent out to him by Government, from the death of comrades and helpers, including his wife and Bishop Mackenzie; from the abandonment of the Universities Mission; from the opposition of the Portuguese authorities; but mainly from the distressing discovery that, encouraged by Portuguese traders, the slave-trade was extending in the district, and the slave-traders using his very discoveries to facilitate their infamous traffic. At length a despatch recalling the expedition was received, July 2, 1863. Livingstone, at his own cost, had brought out a new steamer, but she could not be put on the lake. Depressed though he was, he explored the northern banks of Lake Nyassa on foot; then in his own vessel, and under his own seamanship, crossed the Indian Ocean to Bombay; and after a brief stay there, returned to Britain, reaching London on July 23, 1864. At home Livingstone had two objects--to expose the atrocious deeds of the Portuguese slave-traders, and to find means of establishing a settlement for missions and commerce somewhere near the head of the Rovuma, or wherever a suitable locality could be found. His second book, "The Zambesi and its Tributaries" (1865), was designed to further these objects. He was again received with every demonstration of honor and regard. A proposal was made to him, on the part of the Royal Geographical Society, to return to Africa and settle a disputed question regarding the water-shed of Central Africa and the sources of the Nile. He said he would go only as a missionary, but was willing to help to solve the geographical problem.