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utmost difficulty in distinguishing these artificial chips of flint 
from natural splinters, it is necessary for me to explain, at this 
point, how such artificial fractures differ from natural ones ; and, 
for this purpose, I shall have recourse to the most primitive 
method of producing a flint flake. 
“Let us suppose that the primitive savage required a 
cutting instrument, and that among the flints near at hand there 
were none with such naturally sharp edges as would fulfil his 
purpose. By experiment and research we know, in such a case, 
he selected from the flints near at hand one about the size of his 
fist, to serve as a hammer, and another of a convenient size from 
which to strike chips or flakes, which would also serve for cutting 
purposes. If the flint to be chipped was small, he held it in his 
hand to undergo the operation. If too large to be held comfort- 
ably in the hand, it was probably rested on the thigh: then, with 
a well-directed blow from his hammer-stone, he struck a chip 
from the other flint. Let us now examine such a chip or flake, as 
it is technically termed. We shall first observe that it has a flat 
top upon which the full force of the hammer-stone was concen- 
trated. Directly underneath this flat top, and on the smooth side 
of the flake, which fits into the hollow from which it was struck, 
we observe a little rounded protuberence ; this is known as the 
bulb, or cone, of percussion. In a typical flake we then notice 
the existence of approximately concentric rays covering the flat 
surface of the flake on the same side as the bulb of percussion. 
In some instances these rays and the bulb of percussion are so 
pronounced as to give the flake the appearance of a fossil shell 
cast in flint ; the bulb of percussion simulating the umbo or top 
of the shell, and the concentric rays the divisions of its periodic 
growth. To this reremblance is due the coining of the term 
* conchoidal,” or shelly fracture, now applied to the artificial to 
distinguish it from natural fractures which lack these character- 
istics. When we examine the hollow from which the flake was 
detached, we naturally observe the above characteristics in a 
reversed form. ‘This hollow is known as a facet. 
“To proceed a stage further, let us assume our flint chipper 
has struck flake after flake from the same flint till none of its 
original surface remains, the whole being covered with the 
facets of the detached flakes. It is obvious that the next flake 
taken off will bear the imprint of one or more of the facets from 
which the previous flakes were removed. To produce a good 
symmetrical flake from such a core of flint, the blow should be 
delivered directly above the divisional line of two adjoining 
facets, the result will then be that this line will form a ridge 
running down the middle of the detached flake. 
“Flaking with the hammer-stone, as described above, is a 
knack not very readily acquired ; and, where the production of 
long, symmetrical flakes is concerned, it is extremely difficult, 
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