304 SIR RODERICK I. MURCHISON'S ADDRESS— AFRICA. [May 23, 1859. 



traveller could discern nothing beyond the islands termed Ukerewe, 

 but a vast interior sheet of water, which, according to those Arabs, 

 whose information had hitherto proved correct, extended north- 

 wards for upwards of 300 miles. Captain Speke, who estimates the 

 breadth of this internal sea at 90 miles near its southern end, further 

 ascertained that it is fed not only by streams flowing from the 

 mountains which separate it from Lake Tanganyika, but also by 

 other streams, many of which, meandering in the lower plateau 

 to the west of the lake, constitute, like the internal rivers described 

 by Livingstone, a watery network which when supersaturated by 

 the rains burst and overflow the country. 



Seeing that this vast sheet of water extends due northwards, 

 ascertaining by his thermometer that it was nearly 4,000 feet above 

 the sea, and knowing that its meridian was nearly that of the main 

 course of the White Nile, Captain Speke naturally concludes that 

 his Nyanza is the chief source of that mighty stream on the origin 

 of which speculation has been so rife. This view seems to coin- 

 cide with the theoretical speculation laid before this Society by myself 

 in preceding years, and is in accordance with the data worked out by 

 Livingstone, of a great interior watery plateau subtended on its 

 flanks by higher lands, and from which interior plateau the waters 

 escape to the sea by favouring depressions. 



The physical configuration cf the land to the east of the great 

 Nyanza Lake is indeed strongly in favour of this view. On that 

 side, and at a distance of about 200 miles from its banks, the eastern 

 coast range of Africa rises from 6000 feet in the latitude of Zan- 

 zibar (where it was passed by our travellers) into a lofty range or 

 cluster, of which Kilimanjaro forms the southern and Kenia a 

 northern peak. 



If the assertion of Rebmann and Krapf be accepted, that perpetual 

 snow lies on those mountains, though the able critical essay of Cooley* 

 had induced me to suppose that these missionaries might have 

 been somewhat misled, the summits of these mountains must have an 

 altitude of upwards of 18,000 feet. At all events it is granted that 

 they are the highest points of this coast range. Now, whilst streams 

 descending from the western flank of Kenia (Kilimanjaro is too far 

 to the south) may probably be feeders of the great Nyanza Lake, 

 which occupies a long lateral north and south depression in the 

 plateau on the west, we know from its meridian as now fixed, that the 



* See Cooley's * Inner Africa laid Open,' p. 126. 



