How to Study Architecture by Charles H. Caffin (free reads .txt) 📕

built by Hadrian, A.D. 120-124. The Rotunda occupies, as we have said, the site of an ancient nymphæum, the floor of which, however, was raised 8 feet. Agrippa’s portico was removed from the south to the north side and set up with a front of 8 columns instead of 10. There are 16 in all. The portico is supported by 16 Corinthian columns, each a granite monolith 42½ feet high, with marble Corinthian capitals. The tympanum was originally filled with bronze reliefs, representing a gigantomachia, or battle of the gods and giants.

The walls of the rotunda, which are of solid tufa concrete, faced with thin bricks, are nearly twenty feet thick. This mass was partly to support the dome and partly to admit of eight recesses, opening from the interior. One forms the entrance, while three of the others are semicircular in plan and the remaining four rectangular. The exterior walls, carried far above the spring of the dome, was veneered with porphyry and marble and enriched with Corinthian pilasters and sculptured ornament, a considerable part of which still exists.

Meanwhile, it is the interior of the building that presents the chief impressiveness. Here the walls, which originally were faced with precious Oriental marbles, extend to a height of only two stories, crowned by the vast dome, which in the interior has a height equal to its diameter—one hundred forty-two and one-half feet. It is embellished with coffers, which in order to assist the perspective effect are foreshortened, diminishing in width as they ascend. Thus the gaze is carried up with a sweep to the central aperture at the summit, an open circle twenty-seven feet in diameter, the sole source of light to the interior. “One great eye opening upon Heaven—by far the noblest conception for lighting a building to be found in Europe.” It is as if the soaring imagination of the architect could brook no limit to its vision and must incorporate with his vault the firmament itself. In this magnificent audacity men have seen a symbolic reference to the ancient worship of Jupiter, the god of gods, beneath the open vault of heaven. Meanwhile, the architect may have derived the idea from the old nymphæum with its court open to the sky. And of the two, some will prefer to believe the latter, seeing in it a beautiful illustration of how the artist can and sometimes will use the requirements of practical conditions as an inspiration to the creativeness of his own imagination.

 

From structures circular in plan, we may pass to those in which the plan had the form of an ellipse, or comprised as its chief feature portions of a circle. In the first class belong the amphitheatres and to the latter the various circuses and theatres.

The prototype of all these was the Hellenic Theatre, in the construction of which the architect took advantage of a sloping site.

The Romans, on the other hand, with their general use of arch and vaulting, were independent of natural assistance and usually built their circuses and amphitheatres and theatres in the open.

Circus.—The Roman circus was an adaptation of the Hellenic Stadium, which, however, was used chiefly for athletic games, while the Circus was employed for horse and chariot races. The oldest was the Circus Maximus, situated between the Palatine and Aventine; but the one of which most remains have been preserved is the Circus Maxentius, near the tomb of Cæcilia Metella on the Appian Way. Its plan presents a long rectangle terminating at one end in a semicircle. Surrounding this were tiers of marble seats, supported by raking vaults and an external wall of concrete. At the square end were situated the Carceres or stables and down the centre of the rectangle ran a spina or barricade, with a meta or post at each end to mark the turning points. “To graze the meta” was a Roman saying for the taking of great chances. The course was seven times round and on the top of the spina were oval objects, one of which was removed on the completion of each lap of the race.

Amphitheatre.—The most magnificent of the amphitheatres was the Flavian, known since the eighth century as the Colosseum, probably from the colossal statue of Nero which once adorned it. Its plan is elliptical, the main axis being about 615 feet and the shorter about 510 feet; while the arena, which is oval, is 281 feet long by 177 feet wide. The number of spectators that it could accommodate has usually been stated as 87,000; but the calculation is now said to have been based on a misapprehension of the records and has been corrected to 45,000 seats and standing room for 5000.

The exterior comprises four stories. The three lower are composed of arches supported by intermediate piers which are ornamented with columns, respectively, of the Tuscan, Ionic, and Corinthian orders. The fourth story, which, when the amphitheatre was completed in A.D. 82, appears to have been of wood, presents a wall adorned with Corinthian pilasters. Between these, projecting from the cornice, were corbels, pierced to hold the poles that sustained the velarium or awning. The imposing character of the exterior is due not only to the structure’s immense size, but to the difference in unity secured by the application of the three orders, and to the magnificently sweeping lines of the entablatures.

The interior shows the arena surrounded by a smooth wall, above which the seats rise in concentric tiers to the height of two stories. Here they are bounded by a wall, through which are entrances to the seats while it also acted as a parapet to the upper gallery. The fourth story formed a continuous peristyle. The whole area for spectators was called the cavea.

The place of honour was the circle nearest to the arena, called the podium, in which sat the Emperor, senators, principal magistrates, Vestal Virgins, and the provider or “Editor” of the show. In the amphitheatre at Nîmes seats in the podium were also assigned to the various guilds, whose names are still inscribed upon the seats with the number of places reserved for each.

The principle of construction adopted in the Colosseum, as may be seen from the plan, is that of wedge-shaped piers, radiating from the arena to the exterior. These were connected by vaults which ran downward toward the centre and also in concentric rings, forming passageways to all parts of the cavea. The system is one of concrete vaulting resting on piers of the same material, the latter being reinforced by tufa where the pressure was greater and in the parts of greatest strain by blocks of travertine, four feet thick, sheathed with brick work. “The supports have been calculated at one-sixth of the whole area of the building.”

Theatre.—The form of the Roman theatre grew directly out of that of the Hellenic, but was modified to suit the change which had come over the character of drama. The religious origin of the Hellenic drama had been completely left behind. There was no longer any pretence of a chorus; accordingly the circular space of the orchestra, which had been used by it, was now filled with seats, reserved for persons of distinction. It became, in fact, that part of the auditorium which we still distinguish as the orchestra seats.

Already, in later Hellenic drama, the action of the principal players, which originally had been confined to the orchestra, had extended more and more to the slightly raised platform in front of the proskenion. It was therefore but another step to limit the action to the platform, which, now that the orchestra was filled with spectators, was raised higher from the floor, and, to accommodate the players, was made broader. The separation of the actors from the audience was complete.

The proscenium now became a background, built up to represent a façade of several stories, embellished with pilasters and engaged arches and with niches holding statues. The remains of such a permanent “scene” are found in the Theatre of Orange, in Southern France, where what we now call the stage is 203 feet wide and 45 feet deep, framed in at the ends by return walls at right angles to the proscenium. Near the top of the walls are two tiers of corbel stones, pierced to receive flag-staffs that supported the velarium.

Baths.—Public baths, thermæ, were as necessary a feature of Roman cities as the amphitheatre. Rich citizens, like Mæcenas and Agrippa, set the fashion of building them, and it was followed by emperors seeking to ingratiate themselves with the populace. For the charge for admission was only a quarter of an as—about one quarter of a cent or half a farthing; and even this was waived by certain emperors.

The principal Thermæ in Rome were those of Agrippa, Nero, Titus, Domitian, Commodus, Caracalla, Diocletian, and Constantine. Many of them assumed immense proportions; the ground plan of the Baths of Caracalla, for example, occupying a square quarter of a mile. Besides the actual bathing conveniences, which included hot water baths, vapor baths, cooling chambers and plunges, there were rooms for ball-playing, gymnasiums, colonnades, libraries, theatres, and open courts with shade trees.

From two of the sides of the Baths of Caracalla projected long exhedras, or semi-circular recesses, furnished with benches, which are supposed to have been the meeting places for the discussion of philosophy and poetry. In fact, the great thermæ were the clubs of the period; the resort of all classes, offering cleanliness to the poor, luxury to the rich, and healthful exercise and opportunity of cultured intercourse between those who desired it. And the highest skill was represented in making the walls of the various chambers and reservoirs impervious to moisture, in conducting and heating the water, and in providing flues for hot air.

Basilica.—Equally characteristic of Roman life were the Basilicas. These structures seem to have been intended at first to relieve the congestion of business in the various fora and to afford quiet as well as protection from the weather, for the transaction of business. The earliest in Rome was erected B.C. 184 by Porcius Cato; hence called the Basilica Porcia. Then followed the Basilica Fulvia, Basilica Æmilia, and Basilica Julia, the last being the largest of the five which existed during the reign of Augustus. In A.D. 112, Trajan built the great Basilica Ulpia in connection with his forum, and some two hundred years later was erected the vaulted Basilica of Maxentius or Constantine on the Via Sacra. In all there came to be some twenty basilicas in Rome alone.

One great interest of the basilica halls consists in the fact that from them were derived the plan and form of the early Christian churches. It has been conjectured that the plan of a basilica was derived from that of a Greek temple, the cella walls being replaced by ranges of columns, opening into the peristyle where in turn the columns were replaced by side walls. The colonnades thus became aisles to the central nave; the vestibule being retained at one end and later to be called a narthex, while at the opposite end an apse projected. Here in the Roman basilica were the seats of the quæstor and his assessors, occupied in early Christian basilica churches by the bishop and presbyters.

The interiors of the Roman basilicas present two types of treatment. In the Basilica of Constantine, for example, the nave columns were attached to great piers which supported groined vaults, the thrust of which was sustained by walls at right angles to the piers. These walls divided each aisle into three bays, corresponding to the three bays of the nave, and over each aisle-bay was a barrel-vault, which, being at right angles to the nave, served as extra support to the nave-vaults. Light was admitted through windows in the side walls of the aisles and also through windows in the upper part of the