Anderson, William J.; Spiers, Richard Phené; Ashby, Thomas [Hrsg.]: The architecture of Greece and Rome (2): The architecture of ancient Rome: an account of its historic development ... (London, 1927)

36 THE ARCHITECTURE OF ANCIENT ROME.

Agrippiana, in the Basilica Aemilia, the Basilica Iulia, and in the
temple of Castor and Pollux, to name only a few instances.
A method of construction similar to that described in the case
of walls would seem to
have been employed from
the time of Augustus in
building vaults ; but in
those of great dimensions,
such as the intersecting
barrel vaults covering the
great halls, ribs and ties
of brick were employed
first, to economise the
centering.1 The principle
is already seen in the
aqueduct which Nero
constructed across the
Caslian to the Palatine ;
but the first dateable
instances belong to the
time of Vespasian, and
are to be found in the
vaulting of the lower
arcades of the Colosseum.2
Others, of the time of
Domitian, may be seen
in the so-called temple of -
Augustus {infra) and else-
where in his palace on the
Palatine, and in the crypto-porticus of his Villa at Albano
(Plate X) ; while intersecting ribs are first found in the villa
known as Sette Bassi, half-way between Rome and Frascati (about
140 a.d.).3 Hadrian’s villa provides an interesting example of the
passage from an octagon to a circular vault in the domed hall of
the Piazza d’Oro (Fig. 7), and the flat dome with triangular
1 The various methods employed are clearly set forth in M. Choisy’s l’Art
de batir chez les Romains, and in Viollet-le-Duc’s Dictionnaire Raisonne
under the article “Voute.”
2 Rivoira, Roman Architecture, 92.
3 Papers of the British School at Rome, IV, 102, 111 : Rivoira op. cit., 140
sqq.

J'


Fig. 7.—Domed Room in Piazza d’Oro, Hadrian's]
Villa.