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Full text of "The Legacy Of Egypt"

146 Mechanical and Technical Processes. Materials
by vibration and the efficiency of the work depends on the
quality of the blow; one strength alone does the job: harder
or lighter blows have no effect. The same result can be seen
to-day in boring holes to take blasting charges in the hard
rocks by a 'jumping-iron'. As for wedges, traces of wedge
slots can be seen in thousands in the Aswan quarries and-
eisewhere, some of enormous size. Many of these functioned
together with metal wedges flanked by thin sheets of a softer
metal (now known as feathers) and struck with a heavy hammer.
Another method was to split the granite by means of wooden
wedges made to expand by wetting them. A method I have
used in an experiment on granite has been to cut the slots
with sides nearly parallel, hammer in wedges of a non-oily
wood, such as beech, which had previously been wetted for
an hour or more, split the wedge with an adze or chisel, and
hammer in another on the top of it. The wood expands in
about 10 hours. My reason for believing that the Egyptians
used this method is that here and there wedges have functioned
in positions where no heavy blow could have been delivered.
To-day wedge slots are made with steel points which have to
be frequently re-tempered and re-sharpened. The ancient
examples all seem to have been made with a tool akin to a
mason's pick. I have never found any traces of one which had
been drilled. The colossus, once clear of the parent rock, was
pounded into shape by the dolerite balls or pointed hammers,
but parts too deep for the balls to strike were operated on by
a metal pick-like tool. Once the colossus had been reduced to
its required shape it was left in its rough form and put on a sled,
which was either dragged directly over sleepers or, if the
colossus was very large, over sleepers in conjunction with
rollers. In the tomb of Thut-nakht at El-Barsha such a colossus
is depicted being dragged by 172 men. Once the colossus had
arrived at its destination or workshop, the picking was con-
tinued with tools of ever reducing size. A point was reached,