Fig. 5.4 Palestrina, Sanctuary of Fortune. Model from southwest, showing buttresses, and ramp from Hemicycle Terrace to Cortina Terrace. (H. Kähler, Ann. Univ. Saraviensis 7 [1958], Pl. 39)
The stair which divides the Hemicycle Terrace leads to the Terrace of the Arches with Half-columns (V), also symmetrically planned on the axis of the stair. There are nine deep arches on either side of the stair. Possibly these were stalls for the various guilds—wine merchants, wagoners, cooks, weavers, garland-makers, second-hand dealers, money-changers—who, as we know from inscriptions, made dedications to Fortune, and had a financial interest in her Sanctuary. Here again close observation has enabled the excavators to tell exactly how the façade of this terrace looked when it was new. The even-numbered arches are narrower and lower than the odd-numbered ones, are left rough within, and are floored with a pebble fill, from all of which it is inferred that they were not meant to be seen. Sills found in situ, and uprights, cornices, and volutes, found on the Hemicycle Terrace, where they do not fit into the architecture, and therefore must have fallen from above, can be restored as blind doors set in the walls which closed the even-numbered arches. Small travertine panels, with a molded surround, and a cornice above, found on this terrace, will have been set into the wall on either side of the blind doors, at lintel level. The same decorative motif was found in place on the back wall of the basilica area in the lower zone. The repetition of motif makes an aesthetic link between the two levels. The odd-numbered arches are mosaic-paved and plastered, and were therefore meant to be visible. Enough remains in place to show that the profile of the arch was set with tufa blocks supported on pilasters. These alternating open arches framed with pilasters and closed arches with blind doors all supported an epistyle and cornice which in turn supported the parapet of the Cortina Terrace above.
The Cortina Terrace (VI), nearly 400 feet deep, was a hollow square, open to the south except for a balustrade, closed to the east and west by a three-columned portico, connected at the back (north) with a lithostroton-paved vaulted corridor, called a cryptoporticus, which runs under the stair to the semicircular Terrace VII. Again, similarity of plan and décor ties the whole ensemble together. (Nowadays, the approach to Terrace VII is by a double-access stair, but this is of the seventeenth century.) At the back of the terrace, six arches, three on either side of the central stair, gave access to the cryptoporticus. At either end of the three-arch sequence is an arched projecting fountain house in appearance not unlike a Roman triumphal arch, with a pair of narrow windows in its back wall, opening on the cryptoporticus. Heavy deposits of lime on the back wall suggest an arrangement whereby persons passing through the cryptoporticus could look out through a thin sheet of water onto the Cortina Terrace. Enough traces remain to restore on paper the three-columned portico on the east and west. It was roofed with a pair of barrel vaults, coffered like the ones in the hemicycles of Terrace IV (another aesthetic link), and roofed like the great east-west ramps which connect Terraces III and IV. The portico’s outer walls were buttressed, and the north-south ramps from the Hemicycle Terrace also helped to counter the outward thrust.
And so we come to the exedra, the seventh of the superimposed terrace levels, a most holy place, where the priests could appear and offer sacrifice on an altar in full view of the faithful assembled on the semicircular steps. At the top of the exedra there now rises the splendid semicircle of the Barberini Palace, but plate glass let into the museum’s ground floor paving shows the tufa footings of a semicircular series of columns, which must have been the middle set of another double portico answering to the one on the Cortina Terrace below, and, like it, double-barrel-vaulted and pitch-roofed, but of course semicircular in plan instead of U-shaped. Access to the porticoes was not on the central axis of the whole complex, but by a short narrow stair at either end of the exedra. (We shall see how Hadrian, too, centuries later, liked these split-access arrangements.) But, though there is no direct approach, the distance between the columns on either side of the main axis is extra-wide, to give a better view of the circular building (tholos) above and behind, the culminating point of the whole plan, where the cult statue was placed.
Fig. 5.5 Palestrina, Museum. Sanctuary of Fortune, model.
(J. Felbermeyer photo)
Such is the careful plan of the complex, justifying this detailed treatment because it is a turning point in the history of Roman architecture, perhaps the most seminal architectural complex in the whole Roman world. Everything ([Fig. 5.5]) centers on an axis, everything rises, aspires to the apex at the cult-statue, embracing a superb and at each level more extensive view of the plain stretching away southward to the sea. The materials and technique with which this form is realized and supported are interesting in themselves and for what they contribute to the dating of the Sanctuary. The basic materials are tufa, limestone, and concrete; no marble is used except in statuary. Limestone, which in Roman architecture comes to predominance later than tufa, is used for the facing of polygonal walls and opus incertum, for décor (e.g., the Corinthian capitals of tufa columns), for pavements. The limestone spalls or chips left over from the facing of opus incertum were used in concrete cores and for fill. Tufa is used for footings, structure in squared blocks (e.g., caissons for concrete), the voussoirs, or wedge-shaped blocks, of arches, column drums, the core of stuccoed decorative elements, cornices, corners. Both materials are subordinate to concrete.
The use of concrete at Palestrina amounts to an architectural revolution, and, as often, the revolution in taste is combined with a revolution in materials and methods. This strong, cheap, immensely tough material enabled the architect to enclose space in any shape; henceforward architects could concentrate on interiors, and the day of the box-like temple was over. The architectural history that culminates in the Pantheon begins here. The architect was clearly more expert in the use of concrete than in the use of stone. Palestrina concrete is hydraulic, a combination of limestone chips and mortar made of pozzolana (volcanic sand) and lime. Concrete footings, Fasolo and Gullini found, go down to bedrock everywhere; e.g., each of the three rows of columns of the Cortina Terrace portico rests on a foundation wall of concrete based on bedrock, while the space between is hollow, to relieve weight. For the same reason the whole hollow square of the Cortina Terrace rests on a series of rectangular concrete coffers with a stone fill. The result of this use of concrete is that the whole Upper Sanctuary is structurally a single unit. Each level is planned as a step toward, and a retaining wall of, the level next above. The stresses, Fasolo reports, are never more than about three pounds per square yard for walls and eight pounds per square yard for columns; this in a structure which is in effect a skyscraper 400 feet high. There is repetition of motif throughout, not from paucity of imagination, or because it is the easy way, but of set aesthetic purpose, to emphasize the concealed structural unity and to use the functional parts of the complex to give architectonic unity to the whole. Thus the upper hemicycle stair repeats the two hemicycles of the lower terrace, and the relation between them is a triangle, which repeats in a different plane the triangle of the double converging ramp. The arches are treated as beams to bear the weight of stone construction, and the stone construction is a caisson for the concrete.
Fasolo and Gullini argue ingeniously for a date earlier than Sulla for the Sanctuary, but their arguments have not found general favor. The most that can be said is that certain inscriptions mentioning restoration, reconstruction, or dedications to Fortune earlier than 80 B.C. imply a previously existing and probably much simpler structure, centering on the east half of the Hemicycle Terrace, but nothing in the technique or materials now visible or inferred requires other than a Sullan date for any part of the Sanctuary.