The most imposing Roman baths remaining today are those of Caracalla, south of the Golden House and the Palatine, and those of Diocletian to the north. The Baths of Trajan, probably planned by the architect of his forum, were the model for these later baths.
The Baths of Caracalla, second largest in ancient Rome, are the best preserved of all, and give a clearer idea than any others of these great establishments which once played so important a part in Roman life. The Roman baths were not only bathing places but also immense club houses. Admission to many of them was free, while others collected a small fee. In none of the larger ones, at least, was entrance expensive, though considerable could be spent for extra services or in the shops with which they were equipped. They contained libraries, exhibition halls, lounges, covered promenades, areas for games and exercises, and extensive gardens; everything, in fact, to make the day pass pleasurably. This combination of care for body and mind together was a contribution to civilization lost for centuries after the Empire's decline. The number of baths varied considerably from time to time; by the fourth century A.D. there were probably nearly a thousand, large and small, within the city. Many were open to both men and women, though probably at different hours.
Caracalla opened these baths in A.D. 216; they had probably been begun by his father about 211, and were not finished until some years later. Their alternate name, the Antonine Baths, comes from the family name that Caracalla had borrowed from the great Antonine dynasty of the second century. Like most of the baths built by the emperors, Caracalla's were set in an immense, rectangular walled park, decorated with fountains, flowers, and works of art. The baths themselves opened off a great hall 183 feet long and 79 feet wide, covered by a crossvaulting supported by huge masonry piers. This type of hall was the inspiration of the main waiting room of the Pennsylvania Station in New York, which employed similar forms of vaulting, clerestory lighting, ornamental columns, and end colonnades, in a considerably larger space. North of this hall lay the frigidarium, or cold bath; south of it, the calidarium, or warm bath. At each end was a peristyle open to the sky in the centre but surrounded by a covered portico; these may have been gymnasiums.
In addition there were many rooms for special baths and treatments, for cooling down, and for dressing. Underground there still remains a network of tunnels and staircases along which slaves scurried to serve the patrons without disturbing them; chutes for the disposal of laundry; and pipes and channels for heat and water. Originally the brick-faced concrete walls were covered with stucco painted to imitate marble and were enriched with marble trimmings. Tall columns of grey granite stood against the piers of the central hall; the only one remaining is now in the Piazza Santa Trinità in Florence. A few fragments of these decorations are still left within the baths, but on the whole there is little except the brick and concrete shell.
The magnificent water supply of ancient Rome was primarily designed for public rather than for private use, and supplying the baths was one of its most important functions. The aqueducts which carried water to Rome from the distant hills were among the foremost responsibilities, at first of the Roman officials and later of the emperors. The water for the Baths of Caracalla was supplied by a branch which that emperor constructed from the Aqua Marcia, an aqueduct built about the middle of the second century B.C. Neglect of the aqueducts would, of course, soon destroy the usefulness of the baths. Early in the sixth century A.D., Theodoric and his minister Cassiodorus were fully aware of the ever-increasing danger of such neglect, for Roman resources and manpower were declining rapidly. Cassiodorus exhorted the custodians of the aqueducts in a form letter which is one of the most illuminating documents of the time:
'Though all the buildings of Rome are wonderful, and one can scarce for this reason say which are the chief among them, we think a distinction may be drawn between those which are reared only for the sake of ornament and those which also serve a useful purpose. . . . In the Aqueducts of Rome we note both the marvel of their construction and the rare wholesomeness of their waters. When you look at those rivers, led as it were over piled-up mountains, you would think that their solid stony beds were natural channels, through so many ages have they borne the rush of such mighty waters. . . . These artificial channels, the work of the ancients, never perish, if reasonable care be taken of their preservation.
'Let us consider how much that wealth of waters adds to the adornment of the City of Rome. Where would be the beauty of our Thermae, if those softest waters were not supplied to them?'
Cassiodorus lived to see the damage of the Gothic siege and the beginning of the water shortage which led to the baths' decline and lasted throughout the Middle Ages. The main channel of the Aqua Marcia was cut, with the others, during the siege Of 537-538. It was repaired several times and it is not known exactly when its waters ceased to flow. By the tenth century, however, if not earlier, the city was depending for its water on springs, wells, the brook Marrana, and the Tiber. These could furnish household supplies for the shrunken population of medieval Rome, but the baths and other public conveniences which depended on the aqueducts had ceased to function.
The Middle Ages had lost all conception of the busy, closely knit social life of such a city as ancient Rome. To them the rich materials and remains of complicated heating and plumbing arrangements seemed appropriate only to royal dwellings. The early versions of the Mirabilia simply note under the heading of Thermae the names of the baths which the authors knew, among them the Antonine and those of Diocletian. Later versions expanded their explanations of these rich and mystifying structures: 'There be called thermae great palaces; having full great crypts under ground, wherein in the wintertime a fire was kindled throughout, and in summer they were filled with fresh waters; so that the court dwelt in the upper chambers in much delight.'
In spite of their imposing remains, the Baths of Caracalla are not mentioned as often in the Middle Ages as those of Diocletian. From the sixteenth century on, however, there are many references to the works of art found among the ruins of Caracalla's baths, which had the reputation in ancient days of being the most richly adorned of any in the city. Three of the best-known pieces of sculpture now in the National Museum at Naples were discovered here in the 1540's--the group of the bull on which Dirce was bound by Amphion and Zethus, the colossal statue of Flora, and the Hercules Farnese, which ranks close to the Laocoön in influence on later sculpture. Originally belonging to the Farnese family, these statues, like the gardens on the Palatine, passed by inheritance to the rulers of Naples. Other statues, elaborately carved capitals, a great number of architectural carvings, and some fine mosaics were found in and about these baths from the sixteenth well through the nineteenth century.
The spasmodic early excavations made for the purpose of finding works of art were followed in the nineteenth century by more thorough exploration devoted to the study of the baths themselves. The resultant clearing away of the debris of centuries took with it most of the luxuriant growth which had made these baths a rival of the Colosseum. Charlotte Eaton, visiting them in 1818, gave a delightful picture of them in their uncleared state: 'We passed through a long succession of immense halls, open to the sky, whose pavements of costly marbles and rich mosaics, long since torn away, have been supplied by the soft green turf, that forms a carpet more in unison with their deserted state. The wind, sighing through the branches of the aged trees that have taken root in them without rivalling their loftiness, was the only sound we heard; and the bird of prey, which burst through the thick ivy of the broken wall far above us, was the only living object we beheld.' In those days of neglected loneliness, heaps of fallen masonry piled up against the piers made it easy to reach the crumbling stairways leading to their tops, where romantic visitors sometimes climbed to meditate in solitude. It was here that Shelley worked, in the spring of 1819, upon Prometheus Unbound, noting in its Preface:
'This poem was chiefly written upon the mountainous ruins of the Baths of Caracalla, among the flowery glades and thickets of odoriferous blossoming trees which extend in ever-winding labyrinths upon its immense platforms and dizzy arches suspended in the air. The bright blue sky of Rome, and the effect of the vigorous awakening spring in that divinest climate, and the new life with which it drenches the spirits even to intoxication, were the inspiration of the drama.'
Though the baths have been weeded more than once since Shelley's day, human hands can never completely restrain the luxuriance of growth in Rome. Here and there today, trees spring from a precarious perch and ivy and flowers wave defiantly, while swifts flit in and out among the broken arches in the cool of morning or when the ponentino, or evening west wind of Rome, begins to stir the sun-warmed air.
A new life has come to these once solitary ruins in late years. Since 1937 they have served as the magnificent setting for opera at night during the rainless summer season. The sides of the proscenium arch are the two solitary remaining piers of the circular warm bath which opens from the south side of the central hall. Ramps lead up from the hall to an immense stage, said to be the largest in the world, which affords space for the most elaborate settings and the most spectacular processions.
The steel scaffolding of this stage, which remains in place throughout the year, somewhat mars the picturesque quality of the great hall and its surrounding rooms and closes some of them to visitors. Yet if the romantic peace and luxuriant growth which so delighted the nineteenth century are gone, the magnificent spectacles presented here are in perfect keeping with the ancient Rome which loved imperial display and with the papal city which has welcomed whole-heartedly the pageantry of the Church.