A GLIMPSE OF THE FUTURE 49 



aware, to build steamers now for the Zambezi river 

 traffic drawing more than 2 ft. would be so much 

 money thrown away. When the river is in full 

 flood, of course, the depth is often six or seven 

 times as great, and communication easy with all 

 points below Coroabassa Rapids on the one hand, 

 and the Murchison Falls of the Shird on the other. 

 It would not, I consider, be carrying hypothesis 

 too far to predict a time, still doubtless far distant, 

 when the Zambezi as we know it will cease to 

 exist, and its course, many times wider than it now 

 appears, will present the appearance of a vast, 

 sandy track, over which, after the middle of each 

 rainy season, a shallow trickle of water will pass for 

 a few months seaward, to dry up quickly and dis- 

 appear with the last of the summer rains. In 

 great waterways like the Congo and the Niger, the 

 clayey nature of their banks has doubtless had 

 much to do with their long-continued, and even 

 increasing, navigability ; the rich, argillaceous soil 

 which produced and nourished the immense, almost 

 impenetrable, forests of the higher waters of the 

 Congo, has had an actually preservative effect, in 

 so far as it has been carried down, on the banks of 

 the lower river, by leaving upon them a thick, 

 adhesive, immovable stratum of mud. Not so the 

 Zambezi. Except near the delta, very little mud 

 is seen. Its course, as I have said, is one long, 

 continuous system of sandy islets and visible sand- 

 banks, the component grains of the latter, I doubt 

 not, once part and par«el of a richly productive, 

 alluvial soil area. Again, any steamship master 

 of some years' standing will teU you that in his 



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