DOI Seite / Zitierlink:
https://doi.org/10.11588/diglit.42778#0069
MATERIALS AND MODES OF CONSTRUCTION. 35
regular are the mortar joints. An exception to the rule is presented
by the brickwork of the reign of Nero (Plate XVI) (on the left of
the illustration), which, as seen in the Golden House, is far more
irregular than the very fine facing of the substruction walls which
Trajan built to carry his thermae. It may be interesting to mention
a case in which a concrete wall faced with brick, has been substi-
tuted by Domitian for the back wall of the tabernae, or shops, on
one side of the Horrea Agrippiana, below the Palatine, which was
originally constructed in opus quadratum. The brick facing is
lacking where the ends of the side walls, and the roof of the upper
floor of the shops, served as a sufficient support for the concrete.
In the building of these walls there was an alternation of two
processes. First, one or two courses of facing bricks were laid on
each side ; then a semi-fluid mixture of lime and pozzolana was
poured in, in which the caementa (fragments of stone or brick) were
set by hand.
In many cases this elaborate facing was not left exposed to view
even on the outside of a building, and never on the inside.
In this connexion, however, we must notice the use of ornamental
brick facing, which is especially frequent in tombs, two colours
of brick, yellow and red, often being employed, as in the graceful
tomb (perhaps that of Annia Regilla, and if so, belonging to the
latter half of the second century a.d.) known as the temple of the
Deus Rediculus, not far from the Via Appia (Plate XI). There
the mortar joints are kept as thin as possible, and are often
only 3 or 4 millimetres thick. The exterior is decorated
with pilasters, except on one side, where polygonal columns are
used. At Ostia the arches of large flat tiles were picked
out in red. The use of semi-circular relieving arches over
an opening (especially over a doorway, which is generally formed
of a flat or flattened arch, hardly ever of a semi-circular arch) should
also be noticed. The earliest case known seems to be at the north-
east angle of the Praetorian Camp (Rivoira, Roman Architecture
44, and Fig. 50).
We have not yet noticed the method generally adopted for
building concrete foundations. They were cast in frames formed
by vertical posts with wooden boards nailed on inside.
A characteristic of the architecture of the period of Julius Caesar
and Augustus is the concrete vault springing from a narrow projec-
tion formed by a stone capital or corbel. This is seen in the Horrea
regular are the mortar joints. An exception to the rule is presented
by the brickwork of the reign of Nero (Plate XVI) (on the left of
the illustration), which, as seen in the Golden House, is far more
irregular than the very fine facing of the substruction walls which
Trajan built to carry his thermae. It may be interesting to mention
a case in which a concrete wall faced with brick, has been substi-
tuted by Domitian for the back wall of the tabernae, or shops, on
one side of the Horrea Agrippiana, below the Palatine, which was
originally constructed in opus quadratum. The brick facing is
lacking where the ends of the side walls, and the roof of the upper
floor of the shops, served as a sufficient support for the concrete.
In the building of these walls there was an alternation of two
processes. First, one or two courses of facing bricks were laid on
each side ; then a semi-fluid mixture of lime and pozzolana was
poured in, in which the caementa (fragments of stone or brick) were
set by hand.
In many cases this elaborate facing was not left exposed to view
even on the outside of a building, and never on the inside.
In this connexion, however, we must notice the use of ornamental
brick facing, which is especially frequent in tombs, two colours
of brick, yellow and red, often being employed, as in the graceful
tomb (perhaps that of Annia Regilla, and if so, belonging to the
latter half of the second century a.d.) known as the temple of the
Deus Rediculus, not far from the Via Appia (Plate XI). There
the mortar joints are kept as thin as possible, and are often
only 3 or 4 millimetres thick. The exterior is decorated
with pilasters, except on one side, where polygonal columns are
used. At Ostia the arches of large flat tiles were picked
out in red. The use of semi-circular relieving arches over
an opening (especially over a doorway, which is generally formed
of a flat or flattened arch, hardly ever of a semi-circular arch) should
also be noticed. The earliest case known seems to be at the north-
east angle of the Praetorian Camp (Rivoira, Roman Architecture
44, and Fig. 50).
We have not yet noticed the method generally adopted for
building concrete foundations. They were cast in frames formed
by vertical posts with wooden boards nailed on inside.
A characteristic of the architecture of the period of Julius Caesar
and Augustus is the concrete vault springing from a narrow projec-
tion formed by a stone capital or corbel. This is seen in the Horrea