194 kEV. R. A. BULLEN, B.A., ON EOLITHIC IMPLEMENTS. 
In 1890 Dr. Prestwich laid before the scientific world his 
views as to these rude stone tools being of human origin. 
His reasons for accepting these dressed stones as having 
been worked into shape were briefly :— 
1, They arrange themselves into definite groups 
according to their forms. 
2. The parallelism of the flakes struck off the surfaces is 
not due to natural or accidental causes. 
3. Possible uses can be suggested for some of them as 
tools and implements. 
4, The style of work is the same for those of which the 
uses are obscure.* 
The other causes suggested as capable of producing the 
same rudely chipped edges of these plateau flints are the 
action of frost, of river floods, or of waves on a sea-beach. 
§IV. The action of Frost and Cold. Dawson and Jones.— 
Sir J. W. Dawson, F.R.S.,f in writing of the broken flints on 
natural desert surfaces, and on the sites of old towns and 
similar places, says, “one error in regard to this natural 
breakage deserves notice. It is said it has been caused 
by the alternate expansion and contraction of the flint from 
changes of temperature. But flint is not easily broken in this 
way. I have exposed piles of chalk flints for years to the 
frosts of a Canadian winter, alternating with rain and mild 
weather; and though a few very good flakes and piercers 
were produced, this was only from the surfaces already 
broken; and the number of specimens was very small. The 
actual cause is the pounding of heavy stones borne along by 
torrents, or driven by surf; and the fragments produced in 
this way are often very similar to those produced by 
hammering.” 
It will be seen that Dawson here is speaking only of the 
general form of flakes produced, and not of hammered edges. 
The work on the plateau flints is very often on the blunt and 
not the sharp edges of the flint. 
Professor Rupert Jones has been collecting for years 
specimens of flint accidentally and naturally fractured, 
having any resemblance to man’s stone tools; but these are 
are mostly of small size and have not the general facies of 
the flints of the plateau. 
* Controverted Questions, p. 62. . me 
t Leisure Hour, 1884, p. 490, “Rough Notes of a Naturalist’s Visit 
to Egypt.” 
