172 • SIE JOHN EVAIN^S — THE STOl^E AGE 



almost at right angles to the flat surface. By this means a flake 

 or splinter is struck off. Another blow detaches another flake, and 

 a ridge is left between the two plane surfaces from which the 

 flakes have been removed ; a blow immediately behind this ridge 

 will bring off a third flake of triangular section and having two 

 shai'p knife-like edges. If the blow be administered at some 

 distance from the edge of the flint, a perfect cone will be produced. 

 The flint being elastic, the small circular spot on which the blow 

 falls is driven slightly inwards into the body of the flint ; and the 

 result is that a circular fissure is made which gradually enlarges 

 in diameter as it descends below the surface, so that the piece of 

 flint within the circular fissure is in the form of a cone, with a 

 slightly-truncated apex at the small circle struck by the hammer. 

 It is then an easy matter to strike off the surrounding flint. The 

 cone or portion of a cone made by the blow is known as the bulb 

 of percussion. A cone of flint thus made by a single blow of 

 a hammer is shown in Fig. 1 . 



Fig. 1. Artificial cone of flint. {. 



Gun-flints are manufactured in a rather different manner. After 

 one flake has been struck off, the next blow is given at a distance 

 of about an inch from the spot where the first blow fell, and then 

 others are given at similar distances. By this means splinters are 

 struck off until the block of flint assumes, at least in some portion 

 of it, a more or less regular polygonal outline ; flakes are then 

 struck off by blows behind a flat surface and not a ridge, so as 

 to produce flat four- sided blades with two edges, and these are 

 converted into gun-flints by breaking them into short lengths and 

 trimming them. 



I will now show you, by practical demonstration, how flakes 

 can be struck off a block of flint by blows from a round-pointed 

 hammer. After being thus struck off they can be pieced together 

 again, the flint being built up into its original form, as you will 

 see by Fig. 2. The central block from which flakes have been 

 removed is known as a ' core ' or ' nucleus.' You can readily 

 imagine how one of the simpler forms of hatchets can be manu- 

 factured. The stone hatchet represented on the scale of one-half 

 in Plate IX, fig. 1, has not been ground, but was produced by 

 a series of blows, first on one side and then on the other, so as to 



