330 NATURAL SCIENCE [November 



long by 5 cm. wide. One surface is flat and smooth, while the 

 other is convex and rough, as about one-fourth of it is part of the 

 original surface of the flint. From the convex side two large flakes 

 have been forced off, probably by frost, and no doubt at about the 

 same time as the formation of the flat face. Both sides of the flint 

 are scratched. After the scratching a thin coating of white silica 

 was deposited over the two large-flaked surfaces, filling up some of 

 the scratches. And after this a second set of scratches has cut 

 across the siliceous encrustation. 



The history of the chipping of this specimen is as follows : — The 

 curve at a is the result of natural forces acting on the thin edges of 

 a natural hollow of the flint : the hollow retains the original surface, 

 except at the edge, where three or four small chips have been forced 

 off at a period later than the flaking. The single chip at b has 

 been forced off from the other side of the flint, and probably dates 

 from about the same period as the chips of the a series. 



The almost straight side of the specimen (c) was formed by 

 chipping at a much earlier period, before the stone was stained red, 

 but later than the large frost flakes. 



This specimen therefore exhibits surfaces of four distinct dates — 



1. The original surface of the flint. 



2. The flat side and the two large frost flakes. 



3. The chippings on the straight edge before the iron- 

 staining. 



4. The chippings at a and b subsequent to the iron -staining. 

 No. 4390. A flint from Branshatch (Fig. 2) 14 cm. long by 8 cm. 



wide. This specimen has the original rough surface of the flint on 

 one face and a flat frost-flaked surface ; both have been encrusted 

 by silex. The specimen is much chipped. The chips have been 

 forced off by pressure mostly from the flat side, but at the larger end 

 the chipping was done from both sides, forming a slight irregular 

 ridge. The significant point about this specimen is that most of the 

 chipping occurred subsequent to the dark staining of the flint. 



No. 2711. A tablet of very dark-red flint from Rogersfield, near 

 Ightham, measuring 15 cm. by 9*5 cm. This slab of flint was also 

 chipped before the date of the staining, and also shews chipping by 

 pressure from opposite sides. The chips are of different dates ; the 

 first and second sets are scratched, and the third set are insignificant 

 and irrelevant to the main chipping. The whole surface is encrusted 

 by silica except where it chipped. 



No. Pit VI. A triangular slab of flint (Fig. 3) probably flaked from 

 a large block by frost. The original surface occurs on the convex side 

 and extends over a third of the edge marked a. Ancient chippings 

 from opposite sides occupy the edges d, and some of about the same 

 date occur along b. These chips were all earlier than the iron- 



