Civil Engineering Reference
In-Depth Information
the size and form of the block by way of timber packing pieces. All in all, the device
seems appropriate to special (outsize) instances rather than to standard procedure
(exactly as Vitruvius reports its use by Chersiphron at Ephesos). Nonetheless the
scheme both rationalises the use of the contrivances and also rescues (in principle)
the use of ramps from strong negative criticism by more than halving their required
length (i.e. by increasing their practical gradient from ca 1 in 10 to ca 1 in 4).
Before leaving the subject of earthworks mention may be made of a kindred
subject—the use of sand as a device for transmitting power (in the vertical sense).
h is operates at er the nature of hydraulics. Sand, like liquids (e.g. oil, water) is
incompressible and transmits pressure in all directions. h us to lower a heavy
burden (e.g. a sarcophagus or sarcophagus lid!) it is possible to arrange this (with
security) down a vertical shat by i lling the shat with sand. At the bottom of
the shat some escape hatch is provided which can be closed and opened. h e
sarcophagus or the like is then brought into position on top of the sand i lling,
exactly above its desired position at the bottom of the shat . h e escape hatch
is opened and the sand i lling made to escape under control so that the level of
the sand i lling in the shat slowly descends bearing with it the heavy stone item.
Examples of this procedure can be recognised from the Middle Kingdom onwards
in a funerary context (v Arnold, pp. 74-79; i gs 3.26, 3.27). An unexpected interest
attaches to this device since it is reported to have been used by Chersiphron the
architect of the original Temple of Artemis at Ephesos for setting down into place
massive architraves too leavy to lit . Whereas this notable emergency procedure
was preserved in tradition and related by Pliny (NH 36, 95.9) 500 years later as a
brilliant improvisation, it obviously devolved from Chersiphron's aquaintance with
Egyptian building practice. h eoretically the reverse procedure is possible. A heavy
block can be raised up a vertical shat by continually ramming sand beneath it.
No examples of this practice have been identii ed in Egyptian stone masonry, but
it has been reported as a traditional device known to modern Egyptian villagers
(i.e. to raise up heavy objects which have fallen into pits).
Were massive Egyptian temples erected with no other installations than earth-
works to raise blocks and expert levering to set them in place? It is a striking con-
clusion. Did Ancient Egyptian builders possess no device for lit ing up a weighty
block of masonry from above?
It has long been asserted that Pharaonic masonry was not lit ed by the use of
block and tackle (Clarke & Engelbach, chap. VIII). h is appraisal is based on two
lines of evidence—both negative. No indication of attachments to lit ing devices
are to be seen on blocks, and no material remains of hoisting machinery (cranes,
pulleys) have been identii ed. It is possible to impugn this evidence. Attachments
to masonry can be made by slings which leave no indication on the masonry of
their use. Also some wooden pulley wheels have been discovered (v Arnold, p. 71,
Use of
sand
