Yol. 65.] NEIGHBOURHOOD OP THE VICTORIA FALLS. 395 



Mr. E. J. Clarke, the average rise at Livingstone Drift is about 

 13 feet, floods rising as much as 15 feet, or as little as 10 feet, 

 having been known. 



Tbere are reasons for thinking that the character of the river 

 and the conditions causing the annual flood in the Zambesi were 

 similar while the gorge was being cut back by erosive action far 

 lower down than the present Falls, and that there were, then as 

 now, many miles of rapids above Candahar Island leading to a 

 placid reach in which the water was held up, probably at a higher 

 level, by rapids much longer than at present. Evidence of these 

 conditions remains in the alluvial deposits on both sides of the 

 river. On the right bank below the rapids a narrow terrace, 15 or 

 20 feet high between the river and a steep bank of basalt, widens 

 •out into a flat, thickly covered with trees and bushes, through 

 which it is not easy to make one's way or see much. Towards 

 Dales Kopje it becomes more open, and narrows to less than half a 

 mile, and the basalt begins to show through the soil. On the left 

 bank the flat is clearer of trees and bush, and is traversed by 

 shallow dry watercourses which become flood-channels when the 

 river is in flood. Two of these enter the Zambesi opposite Loanda 

 Island, and another about a quarter of a mile below Candahar 

 Island. Still nearer the rapids a lively brook, fed from the rapids, 

 flowed into the Zambesi in May and June, but dried up as the 

 river continued to fall. Except in the river-bank, where a few 

 seams of fine gravel appear, no sections are to be seen. Bones and 

 teeth of hippopotamus lay strewn on the surface, and there seems 

 to be no reason why remains should not be found buried in the 

 alluvium. The well sunk at Livingstone is suggestive of what may 

 be revealed by future excavations. Under 20 feet of red sand, 

 what is described by Mr. E. J. Clarke, who saw the well sunk, as a 

 grey clayey silt, with stones and pebbles, was reached and was 

 sunk into for 20 or 30 feet. The red sand is probably drift from 

 the slope above ; red sand overlying the grey silt is to be seen in 

 several places between that and the river. 1 The top of the clayey 

 silt seems to have been 20 or 30 feet above present Zambesi 

 floods. 



The flat extends down the Zambesi to beyond the Maramba, 

 merging into the fluviatile deposits of that river which will be 

 mentioned again later. Earther down the basalt rises to the surface, 

 covered in places by gravel which will also be reverted to. 



The artificially worked stones found so abundantly on both 

 banks begin to appear on the right bank about 2 miles above the 

 Ealls, where the alluvial flat ends and the basalt, with the 

 quartzite from which they are made, appears above the soil. 

 Pieces of this material, described by Mr. Lamplugh as chalcedonic 



1 The red sand, where not covered by vegetation, is drifted by the wind. 

 ' Sand-devils ' are to be seen, and there is wind enough to render the river 

 rough for boating in June and July. 



