by
Denys A. Stocks
The Cairo Museum is a treasure house containing many
unusual artifacts. Very often, many of these objects
are ignored as visitors flock to see, quite understandably
and rightly, the more exotic of the displays, particularly
those belonging to Tutankhamen - the enigmatic and
young Eighteenth Dynasty pharaoh.
But if you have a little extra time for viewing in
the Museum, there are two very unusual stone vessels
to attract your attention. The first one is in cabinet
13, on the right-hand side of the entrance foyer.
This vessel, Cairo Museum catalogue number JE6075,
is made of calcite, sometimes known as Egyptian alabaster.
This stone has a dark yellowish hue and is banded
with different shades of white and yellow. Calcite
is a translucent stone. If an electric light, or a
candle, is placed inside a calcite vessel in a darkened
room, you will be rewarded by the stone's exterior
glowing with an exquisite luminosity. Calcite quarried
in Egypt is between Mohs 3 and 4 in hardness, and
my experimental drilling and sawing tests revealed
that flat-ended copper tubes and flat-edged copper
saws, using sand as an abrasive, were needed to drill
and saw this stone. Serrated saws perform poorly on
calcite. Ancient hieroglyphs and reliefs were cut
with flint or chert chisels and punches; an examination
of the marks made with test flint tools on calcite
samples show similarities with hieroglyphs incised
into ancient objects. Test cutting with copper and
bronze chisels showed an unacceptable loss of metal
from their edges.
The cabinet information gives Saqqara as the vessel's
provenance and dates it to the First or Second Dynasty.
The vessel is circular, about 30cm in diameter, comprising
of three, separated circular compartments. Their purpose
is unknown, but they could have been intended for
containing different liquids or fragmented materials.
Two concentric circular ridges, about 2mm wide at
the top, 5mm at the bottom, divide the compartments,
the outer compartment being about 3.5cm wide, the
inner two being about 2.5cm wide. On their inner sides,
the ridges curve downward and inward to the compartments'
flat bottoms; the outer sides of the ridges are vertical.
Near to bottom of the inner ridge, on its curved inside
wall, are four concentric grooves, or striations,
about 0.25mm wide and deep. The two slightly deeper
bottom grooves travel completely around the vessel’s
circumference, the upper two part-way around the circumference.
It is likely that many concentric striations existed
after the initial hollowing procedures, most of them
being completely smoothed away.
There is a lip around the vessel’s outer circumference,
measuring about 4mm in width. The inner, circular
dished section, about 10cm in diameter, has a circular
hole about 2.5cm in diameter, its depth about 4mm,
in the centre. A circular groove, about 2mm in width
and 6cm in diameter, surrounds this hole, but is eccentric
to it. The inner dished section is undercut. Discussion
of the techniques for making the vessel
Although the vessel’s circularity and intricacy suggests
the consideration of a lathe, the tools available
to craftworkers did not allow this technology to be
viable. The test results from cutting calcite with
copper chisels demonstrate the unlikely use of a copper
tool in use with a lathe. In any case, there is no
evidence that lathes existed in Egypt in Early Dynastic
times. The only commonly available materials capable
of incising and scraping calcite were flint and chert.
However, using brittle flint as a tool material for
cutting a rotating piece of calcite is not possible;
the tool would immediately break when pressed against
rapidly moving calcite. In any event, a lathe would
need to be extremely robust, and rotate perfectly
without any shake, to enable accurate machining to
take place.
Using the experimental evidence as a guide, it is
likely that the vessel was roughly shaped into the
desired size with flint chisels, punches and scrapers.
Stone rubbers and finely ground sand were probably
used to finish the surfaces. In accordance with tradition,
the main shape would have been completed first, including
the whole of the top surface, which was slightly curved
before the hollowing of the compartments.
The striations mentioned previously have the appearance
of sand crystal damage seen on other ancient artifacts,
and my experimentally drilled calcite specimens. It
is likely that the craftworker specially made two
tubular drills for the two inner compartments by hollowing
the central portions from the ends of two short wooden
shafts. The wall of each tube would be slightly smaller
than each finished compartment’s width, as a drill-tube
makes a slightly larger tubular slot than the tube’s
actual dimensions. Experiments with reed tubes showed
their ability to drill calcite with dry sand abrasive,
and wooden tubes achieve similar results. A groove
was usually made first to prevent the tube ‘wandering’
around a stone’s smoothed surface. Each tube was carefully
twisted and reverse twisted until the tubular slot
attained the correct depth.
The downward curve on the inner sides of the two ridges
is an indication of a tubular drill operated with
sand abrasive, caused by the tube’s worn exterior
diameter at the business end of the drill. I believe
the outer compartment was fashioned with flint scrapers
and stone rubbers, as was the undercutting of the
inner dished section. A similarly shaped circular
stone borer with sand abrasive probably curved this
part. A copper tube in use with the same abrasive
drilled the 2.5cm-diameter hole. The eccentric groove
may be decorative and originally intended to be concentric.
The second vessel, made of schist, is Cairo Museum
catalogue number JE71295. The cabinet information
indicates that it also came from Saqqara and was probably
made in the First Dynasty. The vessel is located in
the upper west corridor, opposite room 36. Its purpose
was possibly decorative, as it was mounted upon a
pole. The hardness of schist is Mohs 4-5.
Commentary and discussion of the techniques for making
the vessel
This circular schist vessel was originally carved
from a single piece. It was destroyed in antiquity
and rebuilt from the surviving pieces. Schist is a
stone that can be worked with flint chisels, punches
and scrapers, but not with metallic tools. The vessel
was painstakingly chiselled, scraped and ground from
a solid block with the appropriate flint tools and
sandstone rubbers. There are very fine, randomly created
striations all over the vessel’s surface, clearly
the result of rubbing with a fine-grained stone rubber
in a multitude of directions. The design of the three
petal-shaped pieces makes the onlooker imagine that
they have been folded forward from the rim. Not only
have these been exquisitely executed by carving, but
also the ‘spaces’ from which they are imagined to
be folded from must have been drilled and carved to
their finished configurations, leaving the exposed
rim. This is stoneworking at its highest level. A
copper tube and sand drilled the central hole for
the pole after the boss had been carved to shape.
I recommend you look at these stone vessels on your
next visit to the Cairo Museum. You will be enchanted
and mystified by their unique shapes.
References
Stocks, D.A., 1986a. Sticks and stones of Egyptian
technology, Popular Archaeology 7 (3): 24-9.
1986b. Tools of the ancient craftsman, Popular Archaeology
7 (6): 25-9.
1988. Industrial technology at Kahun and Gurob: experimental
manufacture and test of replica and reconstructed
tools with indicated uses and effects upon artefact
production. MPhil thesis, University of Manchester,
England, UK.
1993. Technology and the reed, Manchester Archaeological
Bulletin, 8: 58-68.
Copyright: Denys A. Stocks.