31 



circular pits, or indentations, so eloquent of the power of the 

 sea in its fury to bruise and to pound, but not to flake. And 

 once again, let us look at the sea in its more peaceful mood, 

 when the tiny wavelets ripple in gentle cadence along the 

 margin of the shingle beach, and the sootliing sound of the 

 advancing and receding tide alone fills the ear with that pecu- 

 liar murmur so famihar to us all. What is this sound ? 

 Whence does it proceed ? It is the roUing of pebble over 

 pebble as the waves suck them back to their ocean home. 

 And what is the result that we find here ? It is this ; those 

 angles which yesterday's storm had made are now being 

 rounded and smoothed until the pebbles gradually more and 

 more assume those poHshed circular and oval appearances, 

 so countless in their modifications. If, then, neither the gentle 

 nor the violent action of the sea can produce the forms in 

 question, we certainly cannot attribute them to river action, for 

 here everyone must acknowledge that the smoothing, rounding, 

 and polishing of one side at least of the pebbles is the chief 

 work that the current of the water in its momentum effects. 



It remains, then, but to speak of the agency of frost or of 

 fire, either of which upon flint is somewhat similar. There is 

 a pecuhar kind of dark bluish-coloured flint found at the base 

 of the London clay, which when exposed to the air shivers off 

 in all directions, the slightest tap on one of the pebbles 

 causing it to crumble in the hands. These, then, may be 

 taken as examples of the fractures which occur from the 

 effects of either heat or cold. These angular fragments are, 

 however, very dissimilar from the true " flake," and few per- 

 sons could mistake them. Should anyone wish to make an 

 experiment of heat on flint, let him place a pebble in the fire, 

 and what is the result ? A calcined fracture speaks for itself 



Let us now pass on to the main object of this communica- 

 tion, the process by which the manufacture of flint " flakes" and 

 " scrapers " is accompHshed, and the marks by which they may 



