November 23, 1905] 



NA TURE 



77 



LETTERS TO THE EDITOR. 

 [The Editor does not hold himself responsible for opinions 

 expressed by his correspondents. Neither can he undertake 

 to return, or to correspond with the writers of, rejected 

 manuscripts intended for this or any other part 0/ Nature. 

 No notice is taken of anonymous communications.] 



The British Association and our Colonies. 

 That four hundred members of the British Association 

 have recently visited the principal places of interest in 

 South Africa, that they have been the recipients of magnifi- 

 cent hospitalities, that' they have read papers and discussed 

 points of importance bearing upon the development of 

 African colonies, are facts well known to the reading 

 public. Although so much has been written and said about 

 what the association has done, but little has been con- 

 jectured as to possible outcomes from this remarkable 

 excursion. To many the expedition may appear as a 

 gigantic " picnic," the members participating in which 

 have had a hurried glance at Africa and have returned 

 with that modicum of knowledge which is proverbially 

 regarded as dangerous. If, however, we turn to a list 

 id the names of those who were members of the assoi iation 

 party, and observe that it includes those of recognised 

 leaders in science, literature, and in a variety of pro- 

 fessions, casual conclusions of this nature are at once 

 dispelled. What is realised instead is that South Africa 

 has been visited by a number of specialists whose services 

 an- frequently retained by Governments and corporate 

 bodies. No doubt these gentlemen have learned much, 

 but it is difficult to imagine that they left South Africa 

 without leaving some small return. Now that the) are 

 back in Britain it is tolerably certain that they have 

 brought with them opinions bearing upon railways, mines, 

 agriculture, emigration, and on other matters connected 

 with the development of South Africa, all of which will 

 command attention. A well known eastern country which 

 sends its experts to exploit the western world attains a 

 similar end by systematised departmental methods. 



The benefits of greatest importance, however, ma\ I"' the 

 resultant of personal and friendly relationships which have 

 been established between leading men of science and prac- 

 tical workers in two related countries. These relation- 

 ships should stimulate reciprocity, remove misconceptions, 

 and pave the way to cooperation in various directions. 

 Regarded from this point of view, it is difficult to escape 

 from the conclusion that the meeting of the British 

 Association in South Africa has played an important part 

 in strengthening a union between a parent and its off- 

 spring. 



Should views of this description meet favour, it remains 

 fir members of the British Association and others to 

 consider the possibility of extending the work of such 

 national importance. One method by which this might be 

 attained would be the organisation of an intercolonial 

 meeting of the British Association. The difficulties con- 

 nected with the organisation of such a convention, say in 

 London, to be supplemented by visits to various centres 

 in Britain, to which representatives and visitors from over- 

 sea connections should be invited, have already been in- 

 formally discussed by home and colonial members of the 

 British Association. They do not appear to be insuper- 

 able, and it may be anticipated that such an undertaking 

 would meet with national approval and support. 



John Milne. 



The Stone Age of the Zambesi Valley, and its 

 Relation in Time. 

 Above and below the Victoria Falls stone implements 

 are present in profusion, both in the river gravels on the 

 highest margins of the Zambesi valley and also spread 

 broadcast, along with rolled gravel, on the basalt plat- 

 forms of the ancient river channel below the Victoria 

 Falls. Stone implements are also found in abundance 

 along the highest banks of the Zambesi below the present 

 falls, at the junction of the " desert sands " and the 

 underlying basalts. (I use the term "desert sands," for, 

 though its surfaces are now wooded, it has been deposited 

 under JEoWan desert conditions.) At the base of these 



NO. 1882, VOL 73] 



"desert sands," which form the highest margin of the 

 old Zambesi valley below the present falls, and resting. 

 immediately on the basalt platform, are horizontal beds 

 of chalcedony, ferruginous sandstone, and quartzite sand- 



.1 , these are certainly the products, and have been 



formed at the base of the "desert sands." 



These " desert sands, " which occur on both sides of the 

 Zambesi valley, I was able to examine for some distance 

 below the Victoria Falls. They are of considerable thick- 

 ness, at places fifty, sixtv, and perhaps a hundred feet in 

 depth. The railway from the falls to Bulawayo passes 

 through these sands', and good sections are to be met with. 

 There are no stone implements, pebbles, or stone of 

 any description to be found throughout their entire struc- 

 ture until we reach the very bottom, where the horizontal 

 beds of chalcedony, ferruginous sandstone, &c, rest in situ 

 on the basalts. The chalcedony layer varies in thickness 

 from a few inches to two feet or more. I may here re- 

 mark that the majority of the implements are made of 

 chalcedony ; likewise to a great extent are the pebbly 

 gravels of the river, both above and below the Victoria 

 Falls. Of the thousands of implements and rolled pebbles 

 that I handled, very few were made of any other substance 

 but the rocks that'lie at the base of the "desert sands," 

 and I did not find a single implement made of basalt or 

 dolerite. The quarries of the prehistoric men were the 

 beds that lie at the base of the " desert sands," and when 

 thev were fashioning their implements along the horizon 

 of the chalcedony formation there can be no doubt that the 

 Zambesi was flowing at their feet, a smooth and noble 

 stream, precisely as it flows now through the " desert 

 sands " above trie present falls, and the basalt and dolerite 

 platforms were sunk under the waters of the river. 



The evidences that the river gravels and included imple- 

 ments now resting upon the basalt platforms below the 

 Victoria Falls were deposited by the Zambesi when it 

 flowed at a height of 400 feet or 500 feet above its present 

 level are as follows : — Above the Victoria Falls, on the left 

 bank of the river, near the ferry to Livingstone Island, 

 the river gravels are well in evidence. They consist of 

 rounded pebbles of chalcedony, quartzites, and various- 

 other rocks ; the contained implements are more or less 

 water-worn, and of the same character as those in the 

 gravels below the Victoria Falls. I took from this horizon 

 implements of Palaeolithic type. 



When we pass below the Victoria Falls to the Rain 

 Forest, we can realise withi ut doubt that the Zambesi 

 once flowed over this area, and that its southern cliff must 

 once have been the falls of the river. In the water-worn 

 gullies of the Rain Forest implements and rounded pebbles 

 are to be found of the same character as those in the 

 beds above the Victoria Fall- : they must have been de- 

 posited there by the river when the Rain Forest ana 

 formed part of its bed. When we travel further down the 

 course of the old river-bed we find on the platforms and 

 promontories of the basalt, now eroded by deep lateral 

 ravines, which overlook the zigzags of the canon, where 

 the Zambesi rushes 400 feet below, deposits of implement- 

 bearing gravel. We cannot therefore escape from the 

 conclusion that these implements and pebbles were de- 

 posited there by the Zambesi when it llowed over these 

 surfaces prior to the excavation of the chasm. From these 

 surfaces I took implements some of which, if found in 

 Europe, would be called typical Palaeolithic types. 



If I am correct in my observations as to the method 

 of deposition of these implements, we may be satisfied 

 that an immense period of time has elapsed since Palaeo- 

 lithic man lived on the banks of the Zambesi. We cannot 

 at present measure that period by our chronological record, 

 but we may be satisfied that man lived thin when the 

 Zambesi below the Victoria Falls flowed 500 feet above its 

 present level, and before its waters had carved out through 

 hard basaltic beds the wonderful chasm that now extends 

 for forty miles below the Victoria Falls. Perhaps 

 geologists may in the future be able to arrive at some 

 trustworthy conclusions as to the rate of retrocession of 

 the falls of the Zambesi, and the carving out of its chasm, 

 which would give a more or less accurate determination 

 of the period when primaeval man occupied the Zambesi 

 valley. At present we can only say that a great lapse of 

 time must have occurred; but this deduction, being based 



