The archæology of Rome, Part 7

by John Henry Parker

In the corridors are many remains of the open channels for the water brought from the aqueducts. They are not more than a foot deep, often not so much, being frequently much worn: when perfect they are nearly of that depth, and are lined with the peculiar cement used only for the aqueducts, called Opus signinum, and in Italian, Coccio-pesto. This is an invariable mark of an aqueduct; this open channel must have been brought across from the Cœlian reservoir on the colonnade, shewn upon the coin of Titus. The system of drainage for the rain-water is quite distinct from the channels for the aqueducts.

The floor of the Arena for the gymnastics and the slaughter of wild beasts was of wood covered with sand; on one occasion (as we have shewn) placed upon wine-barrels in the parts that had been flooded; the boards could be removed or replaced with facility. It was full of trap-doors with lifts under them, some large for the animals to jump through, these are over the passage round the outer line, in front of the dens under the podium; others smaller for men and dogs for the hunt; these are on each side of the central passage. Large corbels, with bold projections for placing the boards upon when removed from the floor of the stage, are provided over the stream of water, in front of the podium, but at a lower level; they are in pairs six feet apart, and also served to stiffen the lower end of the masts or poles for the awning; on the surface of them a notch is cut to place the boards upon, and ready access was given by the passage in front of the podium. The gymnasium and the stagna were in one and the same building used for both purposes, and Nero probably built galleries of brick round it for the accommodation of the people, according to the fashion of his time. The exterior was left unfinished for some years, and completed of stone by Titus and the Flavian emperors on a more magnificent scale. The space for the upper galleries was afterwards very much enlarged by building them upon the magnificent double arcades of stone round it, and so completing the great building known as the Colosseum. The straight vertical joint, which is plainly seen between the old brickwork within and these stone galleries and corridors, and the want of any bond between them, is thus accounted for[74]. The upper gallery for the common people was an addition to the original design over these arcades and corridors, and was originally of wood; it was destroyed by fire caused by lightning in the time of the Emperor Macrinus, A.D. 217, and restored in stone in about twenty-three years, having been completed by Gordianus III., A.D. 240. To support this upper gallery of stone at that enormous height vertical piers of travertine are introduced, cutting through the walls of the lower galleries from top to bottom[75]; these walls are of tufa, faced with brick. In several instances portions of these piers of travertine have been removed for building purposes in the Middle Ages, and the space that had been occupied by the piers is left empty. The brick facing of the walls on either side stands just as firm without these travertine piers as with them, a clear proof that their object was to support the upper gallery when it was rebuilt in stone, and not to support the brick walls of the lower one through which they were cut, although they appear to do so. This accounts for the fact that in the brick arches of construction (as they are called), the bricks, originally two feet square, are cut down to a few inches[76].

The names of stagnum or stagna, and naumachia, are evidently used indifferently by the classical authors. It has been already mentioned that in the description of the far-famed palace of Nero, reaching from the Esquiline to the Palatine Hill, Suetonius also speaks of it having “a lake (stagnum) like a sea surrounded by buildings, after the fashion of cities[77].” This could only apply to the Colosseum, and from this it would appear that in the time of Nero the surface could be flooded when required for theatrical display. Probably in two parts, divided by the great central passage or the gulf, and these two parts were called the stagna. It must always be remembered that the one object of the whole building was a theatre for the amusement of the people, very much like the Crystal Palace for London.

The probability is that some of the walls of the buildings of Nero round his stagna were used as part of the lower galleries of the Colosseum; these walls and arches are a mixture of stone and brick, and some of the brickwork has quite the character of the time of Nero, so well known to Roman antiquaries as the finest brickwork in the world[78]. The excavations of 1874 and 1875 have confirmed this opinion; there is a series of arches over the entrance to the dens for wild beasts, under the podium, which are distinctly of the well-known brickwork of Nero. Some of these walls of the substructure are earlier than the time of Nero, others are later, with large repairs of the fifth and sixth centuries. The great external corridors are entirely built of stone, and are evidently added on to the galleries; there is a straight joint from top to bottom in all parts, and no junction with ties anywhere in the original construction. The construction of the walls of the Colosseum in the interior shews such evident patchwork of different periods, that it is impossible to believe they were all built within ten years, as is commonly said.

In many other places besides Rome, part of the amphitheatre was at times filled with water for the exhibition of naval fights, indeed the actual remains of the conduit for the water are shewn in more than one place. At Verona, where the area of the amphitheatre is considerably below the level of the adjacent ground, the conduit or specus is shewn at the level of the second gallery, and below that of the upper one, and the water seems to have gone down a cascade into the end of a corridor or passage at the lowest level. At Capua the aqueduct for bringing in the water and a large drain for carrying it off rapidly, are shewn, both at a low level[79]. In either of these cases, the substructure is to a great extent filled up with vaulted brick chambers separated by passages, but the walls and vaults are lined with that peculiar cement that resists water, and thus a great part of the surface may have been covered with water to a sufficient depth for the purpose. At Puteoli or Pozzuoli, near Naples, the underground chambers of the amphitheatre are unusually perfect, and the brick floor over them, with numerous trap-doors, with deep grooves round the edge for a cover to fit tight over them when the surface was flooded[80]; at Tusculum one of the canals has been excavated, the other is still buried. From these it appears that the naval fights were represented as in a river, rather than in the sea. There are two long straight passages, the whole length of the central space, with no doors in them; and the walls are faced with the peculiar water-cement. These passages are wide enough for a trireme to pass along, and it seems more probable that the naval fight took place on this sort of river than on the whole surface, which would have been necessary for a sea-fight.

This obviously applies equally to the Colosseum, where the great excavations in 1875 shewed that there were two canals on each side of a great central passage, parallel to it and to each other, with an interval of about six feet between them, which was flooded when the water was let in to make two fine sheets of water the whole length of the arena, each about three hundred feet long and fifty feet wide[81]. These were just under the boards, which were carried away and placed on the corbels provided for them in front of the podium, but below the level of the base of it. The walls to support this body of water are unusually thick, and have buttresses on both sides for greater strength[82]. The two canals were not of the same width, but of the same depth, ten feet, with passages, ten feet high, under them. The most narrow canal is nearest to the centre, and has been supported on great beams of wood resting upon the massive walls; the places for the ends of the beams are left at short intervals in the walls. The other and wider canal had brick arches to support it, which remain, though the great leaden cistern in the form of a canal has been destroyed.

The two great lofty walls of tufa are independent of the brick walls supporting the canals. The lifts, or pegmata for the wild beasts, were placed in the outer passage between the two tufa walls, just under the edge of the podium[83]. On each side of the central passage are a series of small square closets for lifts, for men and dogs to ascend from the passages at the lowest level to the floor above, through the trap-doors. These continue visible for the whole length of the surface and central passage. The pavement of these passages is of brick in herring-bone fashion, such as was common in Rome during the first three centuries. Some persons have imagined that the walls are built upon this pavement, but if this is the case anywhere, of which there is no evidence, it would only be a part of the later repairs of the fifth or sixth century.

There are some portions of a third wall of tufa parallel to the other two, and within them; this has been much damaged, and very little of it remains. In one place, near the south-west end, there is an arch in this tufa wall apparently much shaken by an earthquake, and consequently supported by two brick arches of Nero, one under it, the other abutting against it, like a flying buttress in a medieval church[84]. The long, thin bricks of the time of Nero are perfectly well known to all Roman archæologists, and are only met with in buildings of his time. Two other small square chambers, one on either side of the great central passage, also remain at the south end, with an arch of the brickwork of Nero on each side[85]. These chambers are enclosed in stone, so that half the thickness of the wall is of brick, the other half of travertine. This wall, therefore, affords conclusive evidence that there was a great theatre on this spot before the time of Vespasian, and that the tufa walls are earlier than the time of Nero.

We are expressly told that Augustus had intended to build an amphitheatre here, but had not done so. We have no mention of Claudius having built one, we are therefore driven back to an earlier period (probably to the amphitheatre of Scaurus, in the time of Sylla) for the date of the tufa walls, with the grooves for lifts, or pegmata, in them, as has been mentioned. Outside of these great walls of tufa, and under the path in front of the podium, are a number of dens for lions, or other wild beasts of that size[86]. And in front of each is an opening large enough for the animal to pass through into a cage placed on a lift in the passage between the two tufa walls, and in each of these walls are vertical grooves cut in them for the lifts to work up and down; also deeper grooves, about a yard long, for the counter-weights[87]. Behind the place for each cage, in the passage, is a socket let into the pavement for a pivot to work in[88], apparently for a capstan or post to wind the cord upon to pull up the lifts and cages. These cages were of wood, and called pegmata. The word pegma is used in different senses by Pliny, Martial, and others for a wooden box, cage, or framework; and the wild beasts were brought in such cages from the places where they were kept outside the walls, called vivaria.

There were two vivaria, one on the southern side of the Prætorian Camp, of which there are some remains. The evidence for this is an inscription of the time of Gordianus III. (A.D. 241), which mentions a keeper of the vivarium[89] belonging to the sixth Cohort of the Prætorian and Urban[90] Guards. The other was on the southern side of the Sessorium, which was both a palace and a Prætorian Camp.