THE TOOLS OF THE PYRAMID BUILDERS. 
341 
they end about eight inches below the top. The holes in limestone show how 
closely they are placed together for hollowing out 
material ; and the holes were all skillfully spaced 
so that each annular groove of the tool overlapped 
and used as much as possible of the cut next to 
to it, so as to economize labor to the utmost. 
The rock-dressing at El Bersheh shows apparently 
f- 
Fig, 6. Fig. 7. 
the use of large tubular drills for clearing away masses of rock, the surface of a 
large excavated platform being covered with circular grooves, smooth around 
their bottoms as if produced by a continuous cut, and not by chisel work, and 
just joining one another. This could not be the result of cutting out columns, as 
the rock surface is rough-broken both within and outside of the smooth grooves, 
and the grooves sometimes intersect. This work is probably of the twelfth dynasty, 
or about 2000 B. C; and hence later than the pyramid work, which is the 
principal subject of examination in the present inquiry. 
Hence it seems almost certain that the tubular drill principle, of which exam 
pies are here described from one-quarter of an inch to nearly 5 inches in diameter, 
was carried still further into sizes suitable for removing rock on a large scale ; 
sizes which must have needed several men to turn the capstan head of the drill. 
Many other traces of the use of tubular drills were mentioned, as, for instance, in 
roughing out statues, but more. particularly for beginning the hollowing of the 
insides of vases and bowls, which were afterward finished in the lathe. 
A peculiar feature of the cores and holes made by the tubular drills is a cer- 
tain amount of tapering, which is always to be found. This tapering cannot 
have been produced by the rubbing of the side of the drill in turning round in 
the hole, since not only would such a cause be quite inadepuate, but the grooves 
plowed out by the cutting points are just as distinct on the sides of the tube or 
core where it is tapered, as on the lower part. Hence it seems that not only did 
the Egyptians set cutting jewels round the edge of the drill tube, as in modern 
diamond crown drills, but the}'- also set them in the sides of the tube, both inside 
and out Thus the hole was continually reamed larger by the tool, and the core 
turned down smaller as the cutting proceeded, and so the tool could be with- 
drawn more readily from the groove, as the annular space was thus wider at the 
top than at the bottom. Other drills, not tubular, we're used for very small holes, 
such as those in the symbolic, eyes, which are drilled in syenite, 1.2 inches long^ 
and only 0.08 inch in diameter. 
Experiments made by the author seem to show that the minimum pressure 
upon a four-inch drill could not be less than half a ton, and was probably two 
tons, and this is amply confirmed by the speed at which the tool is seen to have 
advanced, and is in accordance with the experience of modern engineers. Upon 
VII— 22 
