332 ROMAN ARCHITECTURE. Part I, As before rein.arkecl, the two parts are certainly not of the same age. If Agrippa built the rotunda as a part of his baths, the portico was added a century and a half or two centuries afterwards, and it was then converted into a temple. If Agrippa built the portico, he added it to a building belonging to Republican times, which may always have been dedicated to sacred purposes. As the evidence at pi'esent stands, I am rather inclined to believe the first hypothesis most correctly represents the facts'of the case. Nero's baths, too, are a mere heap of shapeless ruins, and those of Vespasian, Domitian, and Trajan in like manner are too much ruined for their form, or even their dimensions, to be ascertained with anything like correctness. Those of Titus are more perfect, but the very discrepancies that exist between the different systems upon which their restoration has been attempted show that enough does not remain to enable the task to be accomplished in a satis- factory manner. They owe their interest more to the beautiful fresco paintings that adorn their vaults than to their architectural character. These paintings are invaluable, as being the iTiost ex- tensive and ])erfect relics of the painted decoration of the most flourishing jieriod of the Empire, and give a higher idea of Roman art than other indications would lead us to expect. The baths of Constantine are also nearly wholly destroyed, so that out of the great Thermje, two only, those of Diocletian and of Caracalla, now remain sufficiently perfect to enable a restoration to be made of them with anything like certainty. The great hall belonging to the baths of Diocletian is now the Church of Sta. Maria degli Angeli, and has been considerably altered to suit the changed circumstances of its use ; while the modern Vjuildings attached to the church have so overlaid the older remains that it is not easy to follow out the complete plan. This is of less consequence, as both in dimensions and plan they are extremely similar to those of Caracalla, which seem to have been among the most magnificent as they certainly are the best preserved of these establishments. 1 The general ])lan of the whole enclosure of the baths of Caracalla was a square of about 1150 ft. each way, Avith a bold but graceful curvilinear projection on two sides, containing porticoes, gymnasia, lecture-rooms, and other halls for exercise of mind or body. In the rear were the reservoirs to contain the requisite supply of water and below them the hypocaust or furnace, by which it was warmed with a decree of scientific skill we hardlv srive the Romans of that age credit for. Opj^osite to this and facing the street was one great 1 These baths have been carefully ; is. on the whole, certainly the best ac- nieasured by M. Blouet, who has also ; connt we have of any of these establish- published a restoration of them. This [ nients.
