426 GREAT CHANGES IN THE LAKE. 



tind here and there an occasional baobob, which raises its 

 enormous head high above the highest giant of the forest. 

 The southern coast of the Lake is considerably elevated, and 

 the water is so closely fringed by extensive belts of reeds and 

 rushes that it is only accessible in a few places, or where the 

 native cattle have broken through these natural defenses. 

 The west shore of the Lake is also somewhat raised, though 

 the water is very shallow; but it deepens considerably to- 

 ward its eastern extremity. 



TheNgami must have undergone very considerable changes 

 at diiferent periods. The natives have frequently pointed 

 out to me places, now covered with vegetation, where they 

 used to spear the hippopotamus. Again, there are unmis- 

 takable proofs of its having been at one time of smaller di- 

 mensions than at present, for submerged stumps of trees are 

 constantly met with. This is not, I believe, to be attributed 

 to the upheaving or to the sinking of the land, but that, in 

 all probability, the Lake was originally of its present size, 

 or nearly so, when a sudden and unusually large flood poured 

 into it from the interior, which, on account of the flatness 

 of the country, could not be drained off as quickly as it flow- 

 ed in, but caused the water to rise above its usual height, 

 which, remaining in that state some time, soon destroyed the 

 vegetation. 



Before the Lake Avas known, and when only rumors had 

 reached us of its existence, the natives spoke of its waters as 

 retiring daily to ''feed." But I am rather inclined to think 

 they pointed to a singular phenomenon that I observed when 

 navigating its broad waters, which I then attributed to the 

 Wind, though, on consideration, I suspect it was more likely 

 to have arisen from the effects of the moon's attraction. 



When navigating the Lake, we were in the habit of land- 

 ing every night to bivouac, always taking the precaution to 

 unload the most important articles of our baggage. The 

 canoes were then pushed in shore as far as the shallowness 



