THE FALLS OF THE ZAMBESI 



571 



river was now low, where it is totally 

 impossible to go when the water is high. 

 But though we had reached the island 

 and were within a few yards of the spot, 

 a view from which would solve the whole 

 problem, I believe that no one could per- 

 ceive where the vast body of water went ; 

 it seemed to lose itself in the earth, the 

 opposite lip of the fissure into which it 

 disappeared being only 80 feet distant. 

 At least, I did not comprehend it until, 

 creeping with awe to the verge, I peered 

 down into a large rent which had been 

 made from bank to bank of the broad 

 Zambesi and saw that a stream of a 

 thousand yards broad leaped down a 

 hundred feet and then became suddenly 

 compressed into a space of 15 or 20 

 yards. The entire Falls is simply a crack 

 made in a hard basaltic rocK from the 

 right to the left bank of the Zambesi, 

 and then prolonged from the left bank 

 through 30 or 40 miles of hills. The 

 walls of this gigantic crack are perpen- 

 dicular and composed of one homogene- 

 ous mass of rock. The edge of that side 

 over which the water falls is worn off 

 two or three feet, so as to give it some- 

 what of a serrated appearance. That 

 over which the water does not fall is 

 quite straight. Upon the whole it is 

 nearly in the state in which it was left 

 at the period of its formation." 



Geologists of the present day, how- 

 ever, deny Livingstone's theory regard- 

 ing the phenomenon of the formation of 

 the Falls, claiming that it is due entirely 

 to the processes of erosion, and that the 

 river, by increasing friction through in- 

 numerable ages, has gradually frittered 

 to granular atoms the dense rock and 

 engraved the deep channels of the tortu- 



ous canyon. The basaltic rock which 

 forms the greater portion of Rhodesia 

 is of volcanic origin, proof of which is 

 evidenced in the great lava-flows, which 

 have been poured out in successive 

 waves, covering the country in differing 

 strata of varying porosity hundreds if 

 not thousands of feet deep. Through this 

 the percolating waters have deposited in 

 the cavities the beautiful agates, chal- 

 cedony of various hues, quartz crystals, 

 and zeolites that are found in abundance 

 along the projecting surfaces of these 

 amygdaloidal rocks, many specimens of 

 which I found in the exposed gravel of 

 the river bed. 



It is said that these Batoka lavas, in 

 consolidating, created a system of shrink- 

 age cracks, with occasional long lines of 

 "faultings," or fractures, which consti- 

 tuted planes of weakness that materially 

 facilitated the erosive action of the river. 



If this theory is correct, it is possible 

 that the fissure into which the river 

 plunges at the Falls is due to a fault- 

 plane, where a vertical belt of compara- 

 tively soft material breaks the contin- 

 uity of the harder basalt, and this belt 

 or vein, connecting with others of the 

 same or similar character, has been 

 washed out or excavated by the under- 

 mining action of the river, thus explain- 

 ing the complex phenomena of the Falls 

 and zigzag canyons. 



In the not distant future, when the 

 Cape Town and Cairo Railway has 

 reached the Kongo, and commodious pas- 

 senger steamers ply directly to that great 

 artery of Africa from American and 

 English ports, a trip to the Valley of the 

 Zambesi and its wonderful Falls will be 

 among the popular pastimes of the day. 



