Civil Engineering Reference
In-Depth Information
the sixties of last century. h is revealed that uniformly recesses for swallow tail
cramps were cut in all wall blocks. However, quite amazingly, apart from vestigial
(wooden) survivors, these cuttings were devoid of any cramps. h e only possible
explanation is that the wooden cramps were set as a temporary measure to enhance
the solidity of the masonry during the process of construction (NB the massive
blocks were not clean lit ed into position, but were hauled along and levered about
and into place). h e cramps were then removed from their lodgements when the
course was completed and before being rendered inaccessible by the setting of the
superincumbent blocks. (Wright, Kalabsha 2, p. 76). However from all practical
points of view this explanation seems derisory. Nonetheless a similar phenomenon
has been noted in the (Greek) ashlar masonry at Leptis Magna in Tripoli, and the
same explanation advanced (Ward-Perkins,
Leptis Magna
, pp. 92, 96). h e date
here is late 2nd century AD and neither the masonry nor the province has any
connection with Egypt!
h e history of cramping and dowelling in Classical Greek ashlar was in startling
contrast to the static picture of Egyptian usage extending across two and a half
millenia. It was one of dynamic development. Within a few generations of men
(at most ca 600 BC-ca 400 BC) an occasional auxilliary to i ne stone masonry
became a coordinate component to the stone. h ere were at least the same number
of metal cramps, together with at least the same number of metal dowels as there
were i nely dressed blocks contained in the structure. h ese cramps and dowels
of evolved and dif erentiated forms connected each block of stone to contiguous
blocks of stone in the same course, as also each block of stone to contiguous blocks
of stones in the courses above and below—and the distribution of the cramps and
dowels was as systematic as the setting of the blocks.
h is development of total cramping and dowelling in ashlar masonry can only be
reckoned an expression of Classical Greek rational idealism—the perfect building
construction to correspond with the perfect building design. And with this went
an empirical ef ort to determine the most ef ective form of cramps and dowels to
secure this perfection of construction: metal succeeding wood and the most ef ec-
tive forms proper to metal succeeding one another.
Over all this development arches a question which is never broached in the
manuals. Given that total cramping and dowelling of dry stone ashlar masonry
was the perfect form of i ne stone masonry, the Greeks of the 5th and 4th centu-
ries BC achieved it. But it must be added at great cost. It would be interesting to
calculate what fraction of the total cost of such masonry construction was incurred
on cramping and dowelling. Did cramping and dowelling augment the strength,
solidity and stability of the masonry sui ciently to warrant this added expense?
h is is a question of great interest and worth detailed investigation. Pending such
investigation it is worth while to remark on the sequel.
Cramping
& dowelling
in Greek
ashlar
masonry
202
