436 SCIENCE PROGRESS 



shows the almost unchanged black interior of the flint. The 

 specimen, which measures in greatest length (A — B) 3 T V in., 

 greatest width (C — D) 2 If in., greatest thickness i in., exhibits 

 no incipient cones of percussion upon its surfaces, but the 

 lower thermally broken surfaces exhibit a few small striae. 

 The stone appears to have suffered some amount of abrasion, 

 but at a time prior to that to which the edge-flaking is refer- 

 able. The flaked areas marked L in the illustration are recent 

 fractures. 



Fig. 6. — Provenance the same as specimens represented in 

 figs, i and 3. This specimen (fig. 6) has been made from 

 a tabular-shaped nodule of flint, and exhibits unflaked cortex 

 over the whole of its upper and lower surfaces. The upper 

 surface of the specimen is lightish-brown in colour, while the 

 lower shows little or no staining. The edge-flaking, which has 

 provided the flint with a more or less straight cutting edge, 

 shows a well-marked glaze, and is considered to be the result 

 of blows. The flaked areas of the stone are toffee-coloured. 

 The specimen, which measures in greatest length (A — B) 2\l in., 

 greatest width (C — D) i^z in., greatest thickness § in., exhibits 

 neither incipient cones of percussion nor striae upon its surfaces. 

 The flint shows little or no signs of abrasion. 



Fig. 7. — Found upon the sea-beach at Lowestoft, Suffolk. 

 This specimen, which is of a dark chocolate-brown colour, 

 with a slight bluish tinge upon its upper surface, 1 has been 

 formed, so far as its larger fracture-surfaces are concerned 

 (marked T in drawing), by thermal action. The edge-flaking, 

 which is of a different order from that exhibited by the specimens 

 hitherto described, is considered to be the result of blows. 

 The specimen, which measured in greatest length (A — B) 

 3t^ in., greatest width (G — D) 2\\ in., greatest thickness 

 1 1 in., is heavily abraded and exhibits numerous criss-cross 

 striae and incipient cones of percussion upon its surfaces. 



Figs. 8 and 9. — Represent flints flaked by the author with 

 another stone used as a hammer. 



The above description, together with the illustrations, will 

 enable the reader to form a very good mental picture of the 

 specimens under examination, and it is now proposed to apply 

 the criteria obtained in the experiments in flint fracture men- 



1 The upper surface of the specimens is the surface which is figured. 



