i$4 Mechanical and Technical Processes. Materials
be considered. The arch was known both in brickwork and
in rough stonework, but in monumental masonry no example
of the arch as we know it—the voussoirs mutually supporting—
has been preserved before Roman times. A round roof was
obtained by the Egyptians either by bringing each course slightly
inwards until the two walls met and afterwards cutting the
round roof (Fig. 3i), or by constructing a pent-roof and cutting
the 'arch' in that (Fig. 32).
The subject of masonry in ancient Egypt leaves many prob-
lems unsolved. When one reflects on the considerations that I
have brought forward, incomplete as the length of this article
of necessity makes them, it is a mystery how the great pyramids
could each have been constructed in the lifetime of a man. The
reasons for many of the strange masonic fantasies are even more
perplexing—if reasons there ever were. For instance, why did
Sneferu and Amenemhet III build two pyramids each; what
were the reasons for Djoser's apparent continual changes of
inind while the superstructure and galleries of the Step Pyramid
were being constructed ? Lastly why, in the first gallery of the
Great Pyramid, do we pass, at regular intervals of 10 cubits
(17 feet), clean through the middle of a vast block ?
Apart from gold beads and beads of semi-precious stones, the
earliest jewellery dates from the First Dynasty, the outstanding
example being the armlet found on the arm of the Queen of
Djer. This consists of a 'banner-name' sign, surmounted by a
hawk, alternating in gold and turquoise and supplemented by
amethyst beads. By the Sixth Dynasty the celebrated cloisonne
jewellery appears, the gold cloisons being filled with hard stones
cut to fit. This form of jewellery reached a height of excellence
in the Twelfth Dynasty, some of the pectorals from Dahshur and
El Lahun containing several hundred pieces of inlay. The pro-
portions and fine taste of some of these pieces are unsurpassed
in later periods. By Tut'ankhamun's time, although the motifs
multiply to an enormous extent, the inlay is almost entirely of
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