3GG ]Mr. W. R. Ogilvie-Grant on 



of this is a huge periodical flood which flows down tlie 

 Okavaugo into the marshes of Ngamihmd, of whicli Lake 

 Ngami is really a part. These gradually rise and ovcr- 

 s])read hundreds of square miles of the surrounding country, 

 which is exti'aordinarily flat, the inundation reaching 

 its highest point not during the rainy season, but towards 

 the end of the dry season about August or September. 

 None of this enoimous volume of water finds its way to 

 the sea, but after filling the marshes north of the lake, 

 and formerly the lake itself, flows on down the Botletle or 

 Zonga lliver, and is at length lost by evaporation and 

 percolation. 



No doubt formerly, on many occasions, some of this 

 flood-water has reached the great xMakarikari salt-pan, which 

 is the Ngamiland basin ; but apparently no flood has been 

 sufficiently large to reach it for many years, although an old 

 dry river-bed can be traced a long way to the east of the 

 present end of the iiotlctle. 



It is no doubt only (piite recently that the water- 

 su|)[)ly of Lake Ngami has failed and the lake has partially 

 dried up, for although the processes which have brought 

 about this result must have been in progress long befoi'e 

 Livingstone's visit in 1819, his descriptions of the lake and 

 his illustration clearly shew it to have been then an imposing 

 sheet of w^ater and to a great extent open. To-day Lake 

 Ngami is merely a great reed-bed, which dries up almost 

 entirely before the periodical flood begins. Whether there 

 are any large pools and open sheets of water in the 

 interiorof this reed-bed, which do not dry up, unfortunately 

 I cannot say, as no white man has ever penetrated far 

 into the lake * and native evidence is not unanimous on the 

 subject. I am, however, certainly inclined to agree with 

 those who say that by ]\Iarch the lake is absolutely dry 

 on the surface, except for a few shallow pools at the 

 S.E. corner where it is connected with the Botletle. The 



* It was very uufortunate that this poiut could not be cleared up, but, 

 owing to tlie sudden and serious illness of uiy companion, a hasty retreat 

 had to be made to the railway-liue before tlie exploration of the centre 

 of the lake hud been carried out. 



