KwnowLrs— Lint Implements from North-East of Ireland. 441 
bulb I imagine to be this:—When a blow is struck on some homo- 
geneous substance like flint, a series of waves will be produced 
through the body of the object struck, all radiating from the point of 
impact. The fracture is determined, I believe, by the course of these 
waves and a downward force which is also imparted. The waves, 
proceeding in concentric circles, will cause the cone or bulb, which, it 
will be observed, is sometimes step-like in character. We find in the 
flakes from the raised beach, and also from the interglacial gravels, 
that two and three cones are produced in the same flake. An imper- 
fect hammer, by producing two or three points of impact, would, I 
imagine, originate the extra cones. 
If flint breaks up naturally, or is broken with a massive hammer, 
which strikes a good breadth of surface, no bulb will be produced. A 
rocking motion will, I believe, produce bulbs; and the minute dress- 
ing on the edges of our finer flint implements may have been produced 
in this way, instead of by direct blows. 
On the sea-shore, the rolling of the waves, by knocking one stone 
against another, may sometimes separate a flake with a bulb from a 
piece of flint, but these are mere chips; and oftener we find the 
fractures that have been produced by the wave having no mark of a 
bulb. Anyone who pays attention to the action of water on flint, 
glass, or broken delf, will find that cases of fracture by the action of 
the waves are rare. There is a rounding off of angles, and a tendency 
to turn the object into a rounded pebble; but there is no general 
production of flakes. 
Tue lyerements.—Besides the flakes, we find implements of two 
or perhaps three kinds in the sections and among the denuded mate- 
rials of the raised beach.’ . One kind is rudely dressed, so as to form a 
longish pointed implement, seldom much broader at the base than 
the point. Ihave figured several of these in my previous Paper on 
‘Flint Implements from the North-East Coast’; and I now show a 
very peculiar one from Island Magee. It is very much more mas- 
sive at the point than the butt, and it may possibly have been 
intended for mounting. At the point a small splinter has been broken 
off by the action of the waves; and I may remark, in passing, that 
this fracture shows no sign of a bulb having been produced. The 
implement is seven and a-half inches long; and from about the middle 
9 In an opening paragraph of my previous Paper on Flint Implements I made a 
remark, intended only to apply to some flakes from Larne, in the Royal College of 
Science, to the effect that the objects hitherto found and described as implements 
were in reality only flakes. Mr. W. Gray, M.R.I.A., has reminded me that both 
he and Mr. J. H. Staples have described implements from the raised beach. Iam 
sorry that I have done injustice to Mr. Staples or Mr. Gray, even in a prefatory 
remark. See abstract of Paper, showing result of very careful observation by 
Mr. Staples in Belfast Naturalists’ Field Club Report for 1882, and Mr. Gray’s 
paper in Journal of Royal Historical and Archeological Association of Ireland for 
uly, 1879. 
R.I.A. PROC., SER. II. VOL. LI.—POL. LIT. AND ANTIQ. ZY 
