Civil Engineering Reference
In-Depth Information
(ii) Disposition of Blocks (the masonry pattern)
As a fundamental all blocks, (whatever their form) were set in the wall (whatever
its construction) so as to keep the rising joints of alternate or intermittent courses
exactly in vertical lines (cf the “perpends” of brick masonry). Next it may be
observed that generally in Greek monumental ashlar masonry, the thickness of
the walls was made to acord either with the width of one ashlar block or with its
length. For slight walls of the former class bonding was circumscribed. Isodomic
walls were constructed of blocks set in stretcher bond. If the variety of pseudo-
isodomic masonry was desired dif erent courses could be set with blocks bedded
on dif erent sides. However with the usual form of blocks this did not give much
distinction in course height. More ef ective was to use blocks of two dif erent forms
af ording a greater contrast in course height.
With more substantial walls, a block length in thickness, blocks could be set as
headers and stretchers in the same wall. Here developed bonding patterns were
employed presenting the several aspects of Stretcher Bond, English Bond and
Flemish Bond. If the additional variety of pseudo-isodomic masonry was desired,
then blocks of another format were introduced at regular course intervals. When
a strongly pseudo-isodomic aspect was desired then l at slabs rather than compact
blocks were employed. If the dimensions of the blocks permitted these multiple
block walls could be completely solid construction. However where two stretchers
back to back did not equal the length of one header central cavities occured; and
these were ot en i lled with rubble. Ill 202 gives a conspectus of dif erent forms of
blocks disposed in dif erent manners in a typical passage of Greek Ashlar masonry
of the 5th century BC (the Temple of Poseidon at Sounion in Attica).
Little attention has been given to these bonding patterns in Classical Greek
Masonry and it has not been made clear e.g. what chronological evidence they
of er. Scranton (
Greek Walls
) bases his chronology on modes of facing the blocks
(e.g. margin draughted, bevelled, bossed etc.), however this is entirely a matter
of aspect with no ef ect whatever on the structure of the masonry. Perhaps the
strongly patterned use of headers and stretchers—e.g. three stretchers to a header
in one course (Flemish Garden Wall Bond), or three courses of stretchers to a
header course (English Garden Wall Bond) is more a Hellenistic feature, ca 3rd
century BC (
Greek Walls
, p. 140).
h ere is little detailed record conveniently published on the bonding of Roman
opus quadratum
. Also in this connection the looseness of the term Roman is par-
ticularly vexing. Let alone a possible restriction regionally to parts of Italy, does it
mean building known to have been carried out in some way under 'Roman' direc-
tion or simply any building during Roman rule? Obviously in buildings erected
during Roman rule there is a great dif erence between those in provinces where
Greek ashlar construction was current and those where no tradition of i ne stone
masonry existed.
Bond-
ing in
Classical
Greek
ashlar
masonry
198
199
198b
199
200a-c,
201c
200c
200, 201
