CHAP. XVII THE STONE AGE IN EAST AFRICA 323 



but small fragments of obsidian occurred in the volcanic tuff on which 

 these lay, so the evidence was again inconclusive. I found some more 

 specimens lying beside the track in the Kikuyu country, but still the 

 gun -flint theory seemed a possible explanation. It was not till I 

 reached the highest point of the Kikuyu uplands, before beginning the 

 descent into the Rift Valley, that I found final proofs of a stone age 

 in Equatorial Africa. I was digging in some gravels, searching for 

 fossil shells, when I found a broken obsidian implement of the type 

 known as a " ridged flake." Its edge was chipped, so that there was 

 no question of its artificial origin ; and as it occurred in a patch of 

 sand in a gravel, there was no doubt of its antiquity. After this I 

 found similar implements in many different parts of the country, 

 including the platform on the Kikuyu scarp, the alluvial plain of Lake 

 Suess, the plateau between Lakes Losuguta and Kibibi, the lake 

 terraces around Lake Baringo, on the Sobat pass leading from this lake 

 basin to that of Sukut, on the summit of the pass across the range of 

 Subugu (the Marmanett Berge of von Hohnel), and in many places on 

 Laikipia, as, for example, at Nairotia. 



The best specimens came from a locality near the ford over the 

 Gilgil river, where I found the site of an old settlement. As the 

 implements were associated with hundreds of artificial chips, they were 

 probably made on the spot. Fragments of rough pottery occurred at 

 the same place, but I could find no bones, or tools made from 

 bone. 



The implements found are all made of obsidian, except a borer, 

 which was of pitchstone. They consist of several different types, the 

 principal of which are illustrated by the accompanying figures. 



The commonest implements are flakes, which are either flat, ridged 

 (Fig. 19, No. i), or polygonal. A few with saw edges were met with, 

 such as No. 4. The Gilgil site yielded several cores, from which 

 obsidian flakes had been struck off" (No. 5). Flakes with one end 

 bluntly rounded to use as skin scrapers (Nos. 2 and 3) are also repre- 

 sented. Borers made from long splinter-like chips also occur, as in 

 No. 7. Small knives, made by chipping away one or both edges of a 

 flake, are fairly numerous, while the Gilgil camp yielded a triangular 

 arrow head (No. 6). 



I asked many of the natives whether any such implements as these 

 were used by existing tribes ; but they jeered at the idea that they could 

 ever have been of service to any one. They said the only stones used 

 were pumice, kaolin, and ochre. The first is obtained in many 

 localities, and distributed owing to its value in sharpening spears. The 

 kaolin, or china clay, and the ochre are both used as paints. 



There is, moreover, geological proof of the antiquity of these imple- 

 ments. Both on the summit of the Kedong Pass, and in the old 

 settlement at the Gilgil, the implements were found in situ, in deposits 

 which must have been formed many centuries ago ; in the latter they 



