Ee. 
H.—ANTHROPOLOGY. 153 
piers has been removed for building material, and Lanciani quotes the 
records of the sale of e.g. two or four peperino pillars by the Hospital of 
Sancta Sanctorum at the Lateran, to whom the ground belonged. But, as 
he also points out, sometimes the brickwork was removed and the stone- 
work left ; or, again, the brick facing is sometimes hammered away from 
the concrete. 
As we approach the city, the line of arches was incorporated by 
Aurelian in his city wall. Just before the aqueduct turned to the right 
to cross the Via Praenestina and the Via Labicana by the splendid double 
arch which Aurelian used as the Porta Major (still known as Porta 
Maggiore), a branch diverged from it across the Caelian Hill—the Arcus 
Caelemontani, as they are called in the inscription in which Septimius 
Severus and Caracalla recorded their repair of them,”° or Arcus Neroniani, 
the name under which Frontinus speaks of them. He tells us that Nero 
conveyed the Aqua Claudia by them to the Temple of Claudius, where 
was their distributing tank; the Caelian, Palatine, Aventine, and the 
region across the Tiber were supplied by this aqueduct.24 No doubt 
there was a great ornamental fountain at the Temple of Claudius, from 
which the water fell into the Stagnum Neronis. The arches leading across 
the Caelian are of very fine Neronian brickwork, and so are those leading 
from the Caelian to the Palatine, though they have been largely restored 
by Septimius Severus and Caracalla.?°  Lanciani thinks that there were 
two more tiers of arches above the two now existing”®; but I cannot believe 
that the aqueduct would have carried more, and I therefore believe 
that the syphon of which he speaks was originally constructed by Nero, 
and that it ran over the arches. It was restored by Domitian; a pipe 
bearing his name, about eight inches in diameter, was found in 1742.2? 
Just beyond the Porta Maggiore the Aqua Marcia, with the Tepula and 
Tulia above it, entered the city ; and the three channels may be seen in 
_ section where they pass through the Aurelian wall. The Anio Vetus has 
been found just inside the gate, and the Aqua Alexandrina very likely 
entered the city here also. 
The question as to the amount of water carried by the aqueducts 
depends upon the value given to the quinaria, the official unit of measure, 
1 RY 
explained by Frontinus, who, as cwrator aquarum under Trajan, wrote a 
treatise upon the aqueducts. The most probable value has recently been 
determined?® as 0°48 litre per second or 41°5 cubic metres in twenty-four 
hours ; and we thus get the following table :— 
Quinariae Litres Cubic metres 
(Frontinus). per second. per diem. 
Anio Novus .. BE 4,738 2,274 196, 627 
Claudia .. a: y. 4,607 2,211 191,190 
Marcia .. ah Lg 4,690 2,251 194,365 
Anio Vetus... i 4,398 2,111 182,517 29 
3 O.7.L. vi. 1259. 
24 Frontin. i. 20; ii. 76, 87. 
25 Lanciani, op. cit. 372, attributes them to the Severi entirely. 
26 Ruins and Excavations, 186, fig. 69. 
27 Lanciani, Comentari, 424. 
28 Claudio di Fenizio, in Giornale del Genio Civile, liv. (July 1916). 
29 Livellazione, 77: Lanciani’s estimates, Ruins and Excavations 58, are a good 
deal higher; but cf. Comentari, 573 sqq. 
