Once more, in 1856, the same party started farther south from Zanzibar. Hearing of a great inland lake, they pressed forwards to make an exploration, but were prevented by the Masai tribes. Burton was now laid up with fever, and Speke formed a large party and crossed the Unyamivezi and Usukuma. On July 30, 1858, they were fortunate enough to cross one of the bays of the southern half of Lake Victoria Nyanza. They struck northwards, and, on August 3rd, gained sight of the open waters of the great lake. Speke did not realise the vast area of the lake at this time, and put down its width at about one hundred miles. As he had promised Burton to return at a certain pre-arranged date, he went back to the coast. Burton, however, was unreasonable enough to be displeased with Speke's discovery, and the two fell into strained relations. On arriving at the coast, Speke at once went back to England, and there raised funds to make a longer and more complete exploration. He was naturally anxious to learn more about the great lake in the middle of the continent, and, besides this, he thought that he could demonstrate to the satisfaction of the scientific world that this vast basin of water was the source of the White Nile. Captain James A. Grant asked leave to accompany Speke, and became his efficient lieutenant. Grant was a good shot, a matter of importance, for it was almost certain that the party would have to confront the danger of being surrounded by wild beasts and hostile natives. He was also a good geologist and painted well in water-colours, and proved himself to be a capable lieutenant to the leader of the party. The Indian government sent the expedition a quantity of ammunition and surveying instruments. The party started from Zanzibar for the interior in October, 1860. At Usugara they were detained by the illness of Captain Grant and some of the Hottentot retainers. A number of the instruments were now sent back in order to lighten the burdens, and among other things was returned the cumbrous photographic apparatus, which was the only kind in use in the sixties. At Ugogo serious trouble arose with the native chiefs, who demanded tolls from the party. Many of the remaining porters here deserted, and others were frightened by the hostility of the local tribes. When at length they reached the Unyamivezi most of the beasts of burden had died, and half of the stores they had intended to bring with them were found to have been stolen by the natives. The Arabs here told Speke that there was another lake besides the Victoria, whose waters, according to some, were reported to be salty.