CARCER
the ancient state prison of Rome, situated between the temple of Concord and the curia at the foot of the Capitol (Liv. i. 33: media urbe imminens foro). Cf. Veil. ii. 7. 2; Val. Max. ix. 12. 6; Plin. vii. 212; Seneca, controv. ix. 27. 20; Fest. 264.It was used simply as a place of detention, and not of penal servitude, though executions (i.e. those of Jugurtha and Vercingetorix and of the Catilinarian conspirators) also took place here. The subterranean part was called Tullianum (applied in Amm. Marc. xxviii. 1. 57 to the whole). The name (Liv. xxix. 22. 10; xxxiv. 44. 8; Serv. ad Aen. vi. 573; Calpurn. Flacc. decl. 4: Acta Chrysanth. et Dariae, 25 Oct. p. 483) is by Varro (LL v. 151) and Festus (356) derived from Servius Tullius, who was the builder of this portion of the carcer : while Livy (i. 33) attributes the construction of the carcer to Ancus Martius. Sallust (Cat. 55) describes it in a well-known passage: in carcere locus quod Tullianum appellatur, ubi paullulum ascenderis ad laevam, circa duodecim pedes humi depressus. Eum muniunt undique parietes atque insuper camera lapideis fornicibus iuncta, sed incultu, tenebris, odore foeda atque terribilis eius facies est.
This lower chamber of the building is subterranean and was originally accessible only by a hole in the roof. It is nearly 7 metres in diameter: in the walls only three courses of stone are visible, and it is thus less than 6 feet high: but three more courses may still be hidden by the present floor, and this would give the 12 feet of which Sallust speaks. The building was, according to one theory, in origin a cupola grave, like those of Mycenae: while others think that it served as a water reservoir, and derive the name Tullianum from tullus, a spring. A small spring does indeed still rise in the floor; and the absence of incrustation, used as an argument against the second hypothesis, has little weight, as the water is not calcareous.
It has generally been believed that the cupola was cut by the constructors of the upper chamber; Tenney Frank (TF 39- 47) now supposes, without sufficient reason, that the lower chamber originally had a flat wooden roof, which later served as a scaffolding for the flat stone vault, which dates from after 100 B.C. But the holes to which he points in support of this theory may just as well have been cut for this scaffolding. There is little doubt that the chamber was originally circular (the statement that the straight chord on the side towards the Comitium is of rock, is incorrect). See JRS 1925, 121.
Most authorities attribute to it a high antiquity: but Frank assigns the lower chamber to the third century B.C. owing to the use of peperino (not tufa, as all other authorities state) and the regularity of the blocks, uniformly 56 cm. high: while the date of the drain leading into the forum appears to be debateable.
The upper room is a vaulted trapezoid, the sides varying in length from 5 to 3.60 metres. This Frank assigns to about 100 B.C. on similar grounds; and the vault of the lower chamber, as we have seen, to a slightly later date.
A new facade of travertine was added by C. Vibius Rufinus and M. Cocceius Nerva, consules suffecti, perhaps in 22 A.D. (CILvi. 1539=31674; cf. 9005; Pros. i. p. 428, No. 972; iii. p. 424, No. 395), but, it may be, a good deal later (Mommsen, Westdeutsch. Zeitschr., Korrespondenz- blatt, 1888, 58, puts it a little before 45 A.D. ; cf. ILS iii. p. 342). It was still used as a prison in 368 A.D. (Amm. Marc. xxviii. 1, 57), so that the tradition that it was converted into an oratory in the fourth century is without foundation; and the fons S. Petri, ubi est carcer eius of Eins. (7. 2), cannot have been here (Mon. L. i. 481 ; HCh 421-422).
The name Mamertinus is post-classical.
The building near the Regia, mis-called Carcer by Boni, is a series of cellars,1 and may belong to about 70-40 B.C. (CR 1902, 286; Mitt. 1902, 94; 1905, 116-117; TF 87; HC). See Jord. i. 2. 323-328; RL 1902, 226-239; HC 119- 123; AJA 1923, 397; ZA 60-63; Leclercq in Cabrol, Dict. v. 2053- 2057; HFP 5-8.