Rome

In early Rome ordinary dwellings were straw huts or straw thatched adobe huts, while temples and public buildings were erected in the Etruscan manner to suit the materials of the vicin ity. The Capitoline temple, for instance, had walls of volcanic tuff well coated with stucco to hide the ugliness of the material. The ceiling beams which supported a tile roof were probably held up by a cantilever brace. The roof of the portico rested on four tuscan columns of wood or stuccoed tufa. The wooden architraves were covered with figured terra-cotta slabs that provided some adornment and protection for the beams. The pediment figures were also of terra-cotta. Because of the absence of good building stone the Etruscans early developed for architectural adornment a dignified plastic art in terra-cotta, and its artistic qualities can now be appreciated in the splendid Apollo-figure recently discovered in Veii, a few miles north of Rome. This Etruscan method of build ing sufficed for the city till Greek artists were brought to Rome in the second century B.C. The building of stone bridges and aque ducts during the 2nd century popularized the use of the stone arch. The concrete dome which became so striking an element in later Roman construction was not used to good effect till the latter part of the I st century of the empire when the art of making reliable concrete had been fully developed.

Materials.

Since public buildings were frequently rebuilt and enlarged it is difficult to assign the present remains to their proper epoch, and the accounts of early Roman architecture do not by any means agree as to dates. It is only by careful observation of the materials' used that we can assign the remains of the repub lican period to their approximate periods. Before the Gallic fire in 387 B.C. practically the only stone used was the soft grey volcanic tufa called cappellaccio, the principal source of which was the quarry at the foot of the Capitoline where the Mamertine prison now stands. This is a very poor weathering stone so that it was regularly protected by a coat of stucco when used above ground.

After the Gallic fire, when Rome had gained possession of the Veientian quarries of Grotta Oscura near the Tiber some Iom. north of the city, the yellowish grey tufa of that region came into popular use. This stone was as easily worked as the native one, and- being more uniform in texture was cut into larger blocks of 2X2 feet. The massive fortification walls of Rome were largely rebuilt of this material during the 4th century, as were many of the public structures that had been destroyed by the Gauls. For rough work some very ugly volcanic stone, full of inclusions of black scoria, was also used for a while. This was also found in southern Etruria, and the blocks that were used at Rome and Ostia may have come from the abandoned walls of Fidenae, north of Rome. The grey tufa of Grotta Oscura was the favourite build ing stone of the city for over 200 years, while the scoria-filled stone was soon abandoned.

These materials also weathered poorly and proved too weak for 'Middleton, The Remains of Ancient Rome (1892) ; Lanciani, Ruins and Excavations (1897) ; Delbruck, Hellenistische Bauten (19o7) ; Van Deman, The Date of Concrete Monuments (1912) ; Frank, Roman Buildings of the Republic (1924).

heavy loads. Hence in the 3rd century architects went to the Alban hills for the stronger dark grey tufa (Lapis Albanus, pe perino) when in search for architrave beams and heavy column drums. The Tullianum, Rome's first prison, which required a very hard stone, seems to be the first structure built of this material. It probably was constructed about 25o B.C., certainly not in the regal period as has been supposed. All the large temples built dur ing the 2nd century B.C. used peperino for points of great stress and weight. At the Gabine lake, an old volcanic crater which was nearer Rome, a tufa somewhat rougher than peperino, but equally strong, was then brought into use. This Gabine stone (Lapis Ga binus, sperone) was freely employed in massive walls for a cen tury or more, but its use was limited by the fact that it would not yield to ornamental cutting. Both of these stones were costly because of the heavy transportation charges. Hence during the 2nd century experiments were made with the brown tufas nearer Rome. As can still be seen, the hills of Rome had an abundant sup ply of this brown tufa lying above the cappellaccio, but these hills were now so well covered with buildings that quarrying inside the city was impracticable. South of the Janiculum, on Mt. Verde, a quarry was opened and used for several buildings of the second century and of the early decades of the first. The Mt. Verde stone is hard, close-grained, but too brittle for heavy burdens, and was seldom used after Sulla's day. The brown tufa from the Anio river just above Rome proved to be very strong and uniform, in fact an excellent material except for its ugly appearance. After the fine arches of the Aqua Marcia were built of it in 144 B.C., it remained because of its durability and cheapness the favourite stone for ordinary ashlar masonry for two centuries. This Anio tufa is now to be found in the ruins of more than half of the build ings of the forum. During the 2nd century B.C. two very important discoveries of materials were made. The travertine deposits at Bagni on the road to Tivoli were found. This is a limestone of recent formation caused by the deposit of the carbonate of lime from the hot springs that arise at that point. Since the ground was level and covered with vegetation the splendid deposit had for cen turies lain unobserved. The stone being rather soft when at first exposed is easily sawed and worked. It soon hardens under expo sure. The Romans used it at first with some hesitation, but by Caesar's day they had learned to appreciate its good qualities. During the early empire it was freely used, as may be seen in the massive walls of the Colosseum. Recently this stone has been exported in large quantities to America.