PONS CESTIUS
the modern Ponte S. Bartolomeo, the first stone bridge
from the island to the right bank of the river. It is mentioned only
in Not. app. and Pol. Silv. (545), but probably was built soon after the
pons Fabricius. Several Cestii of some prominence are known in this
period, and the bridge was probably constructed by one of them, while
curator viarum, between 62 and 27 B.C.
In the fourth century the pons Cestius was replaced by what was
practically a new structure, which the Emperors Valentinian I, Valens
and Gratian finished in 369 (Sym. Pan. in Grat. p. 332) and dedicated
in 370 as the pons Gratiani. There were two inscriptions recording
this event, each in duplicate, the first cut on marble slabs placed on the
parapet on each side of the bridge, the second beneath the parapet
(CILvi. 1175, 1176). One of the former
1is still in situ. The pons Gratiani
was 48 metres long and 8.20 wide, with one central arch, 23.65 metres
in span, and a small arch on each side, 5.80 metres wide. The material
was tufa and peperino with facing of travertine, and the pedestals of
the parapet probably supported statues of the emperors as those of the
pons Fabricius did hermae. The construction was rough and characteristic of the decadence, and very little of the earlier pons Cestius could
have survived in the later structure, although the general appearance and
form of the two bridges were doubtless about the same.
The pons Gratiani was restored at various times between the twelfth
century and 1834, but in 1888-1892 the building of the new embankment
and the widening of the channel made it necessary to take down the
old bridge and erect a new one, 80.40 metres long, with three arches.
The central arch of the new structure reproduces the original exactly,
although only about one-third of the old material could be used again
(Jord. i. I. 418-420;
Mitt. 1889, 282-285; Besnier 106-119, and literature
there cited).