34 MR. W. G. CLARKE ON NEOLITHIC MAN IN THETFORD DISTRICT. 
been the case. Some of the duck-bills' were probably used as 
“ strike-lights,” with a nodule of iron pyrites. The length ranges 
from 1 pj to 2 t ^ inches, and the width of the narrow type from 
§ to l-^ inches, the maximum of the broad type being 1~ inches. 
A fact worthy of note is, that out of twenty-one specimens, nineteen 
are hollow-backed, there being a distinct inward curve, the hollow 
being a most convenient place for resting the thumb. 
Hollow scrapers are of comparatively rare occurrence, though 
flakes with a chipped indentation on one side are not infrequently 
found. I have two duck-bill scrapers l T k by § and 2 by lj inches, 
which are hollowed out in the centre of the end of the flake, and 
were probably used for rounding off arrow-shafts. Another almost 
unique type is the double hollow 
scraper (Fig. 4), which in addition 
to the strongly defined and well- 
chipped indentations on each side, 
is also chipped at either end to form 
a semi-circular scraper, an arrange- 
ment of great utility. The face 
represented in the engraving is of 
deep blue flint, whilst the major 
portion of the other face is taken 
up with the yellow crust, no doubt 
for obtaining a firmer hold. To 
type 5a, the most beautifully chipped 
and symmetrical scrapers belong, 
indeed, out of fourteen examples, 
eleven are almost without a flaw. 
Fig- A small specimen, inch in length 
Double Hollow Scraper. and w idth, and ^ inch at base, is 
rubbed' smooth on one side, and is semi-transparent except where 
the bulb makes the thickness greater. The only chipping is on the 
edge and is exceedingly minute. Another specimen is of black 
flint, 2 by 2 j inches, and 1 inch at the base, and would be correctly 
designated a “ knife-scraper,” as the chipping on the back surface, 
about | inch deep, combined with the chipping in front, makes the 
edge as sharp as a knife. The front face is chipped over the entire 
surface, whilst the back is smooth, save the previously mentioned 
narrow band of chipping. The remaining specimens are of the 
