Respecting the length of the Ukara Lake, Sádi was informed that it could be crossed by canoes in 6 full days, paddling from sunrise to sunset; but if the men went on night and day, the voyage is to be accomplished in three days. Now the native craft used upon these dangerous plateau- waters never dare to cross them: the voyager may rush over the narrow parts of the Tanganyika Lake, but of course he would not attempt the physical impossibility of navigating without chart or compass beyond sight of land. It is impossible to believe in a canoe-cruise of 6 days across the lake: it is evident that a coasting-cruise is meant. The total of hours, allowing the day to be 12, and without halts, would be 72. Upon the Tanganyika I estimated the rate at a little more than 2 knots an hour. Thus, in round numbers, we have 145 miles, which probably require reduction: an estimate of the mean amount of error distributed on the whole of Mr Wakefield’s ‘Routes’ gives, according to the annotator, an exaggeration of 1.24 : 1.0; and of course, when estimating the length of these distant and dangerous navigations, exaggeration would be excessive. We may, therefore, fairly assume the semi- circumference of the Ukara Lake at 120 miles, and the total circumference at 240. Sádi, we are told (p. 309), made Bahari-ni on the Eastern shore the terminus of his long journey from Tanga Bandar to the ‘Lake Nyanza’ (Nyanja?). Let us protract the full 145 miles as the exceptional rate of 3 knots an hour upon Captain Speke’s last map, without allowing anything for the sinuosities of the coast, and the end would strike the entrance of ‘Jordan Nullah’ off the ‘Bengal Archipelago,’ about half the width of the so-called ‘Victoria Nyanza.’