ETHNOLOGICAL NOTES 
93 
The implement (Fig. 3) is 10^ inches long, slightly under an 
inch thick, and weighs 3 lb. 1 oz. It is made from a natural 
slab of a slightly vesicular grey volcanic rock, probably 
trachyte. The slab has been chipped to shape, leaving the 
natural weathered surface on both faces. The chipped sur- 
faces have become slightly patinated to a darker grey. There 
are no signs of hammer dressing or grinding. 
IO-- 
9 
a 
7 -- 
6 - 
5 - - 
4 ■- 
3 -- 
2 - 
INCHES 
Fig. 3. 
Implement from Oberon. x i. 
The chipping has been done from both sides, so that the 
edge is in the medial plane. The edge is well defined all round, 
except at the butt and at one corner (Fig. 3, A), where it is 
rather rounded and blunt. For such comparatively intract- 
able material the implement is remarkably symmetrical. 
Both faces are slightly hollow (1/16 in. on one side and | in. 
on the other). The surfaces of the hollows appear to have 
been smoothed by rubbing, as if the implement had been used 
as a lower millstone. The rubbing, which is slight but quite 
definite, extends also over the chipped surface at one side 
(Fig. 3, B-B), and over the same relative part on the other 
face. 
The secondary use of implements as lower millstones is 
found in the large grooved axes of SW. Victoria. Of these, 
about 20 per cent, have semi-spherical hollows on one face, 
and about a further 10 per cent, have them on both faces. 
