212 A FLAKE OF FLINT AND ITS HISTOKT. 



till it assumes Ihe blue-black tint characteristic of the 

 mass. If, however, our flake contains a portion of the 

 external coat of the nodule, we shall see that for about 

 a quarter of an inch in depth the outer layer is far less 

 compact than the rest of the flint, and is of an opaque 

 white colour. In other specimens, again, we shall observe 

 that the colour, instead of the usual deep blue-black, is 

 of a pale whitish-blue, frequently marked by more or less 

 distinct bands. Needless to say that on trying to scratch 

 our flint flake with a knife we shall signally fail, and if 

 any result liappens it will be that a thin film from the 

 metal of the blade will be left on the stone at the jjoin; 

 of contact. 



Our flake will likewise exhibit in great perfection the 

 characteristic conchoidal fracture of flint ; that is to say, 

 its surfaces will be smooth and undulating, swelling here 

 into a prominent convexity, and falling there into a deeper 

 or shallower hollow. Frequently, moreover, there may be 

 observed a number of small parallel wavy ridges on the 

 fractured surface. If we submit the edges of the freshly- 

 broken flake to a series of taps from our hammer, we 

 shall find that a number of smaller flal^es will be readily 

 chipped ofl^, each leaving a separate conchoidally-fractnred 

 surface on the original flake. It is this facility with 

 which flint can be chipped, coupled witli its hardness and 

 the sharpness of its fractured edges, that induced our 

 palaeolithic ancestors to adoj^t it as the material for their 

 various weapons and tools. The figure on the preceding- 

 page of one of these implements exhibits in great perfec- 

 tion the characteristic conchoidal fracture of flint.* 



The extreme development of this peculiar and charac- 

 teristic fracture is, however, exhibited when a large flat 

 surface of flint is struck at right angles by a round- ended 

 hammer. The hammer then comes in contact with a 

 minute portion of the surface of the flint, which mav be 

 represented by a small circle, and as the flint is elastic, 

 " this small circle," as Sir John Evans observes, " is 



* We are indebted to Messrs. Longman and Green lor this and 

 the following figure. 



