HISTORICAL CONSTRUCTION OF WALLS.

SECTION II.

ON THE DETAILS OF ROMAN ARCHITECTURE".

BY R. P. PULLAN, F.R.I.B.A.

THE dates and histories of the various edifices of ancient Rome have ever been matters of dispute. Upon few subjects connected with archæology has there been greater difference of opinion. Niebuhr, Bunsen, Canina, and other eminent antiquaries have maintained opposite theories as to the date and destination of almost every building that once graced the imperial city. Some supposed the temple, now generally believed to be that of Mars Ultor, erected by Augustus, to be that raised by Trajan to his predecessor and patron, Nerva. Many maintained that the temple on the Clivus Capitolinus, now ascertained to be that of Saturn, was the Temple of Concord, rebuilt by Tiberius; others asserted that the Basilica begun by Maxentius, and completed by Constantine, was the Temple of Peace, commenced by Claudius, and finished. by Vespasian: it is still a disputed point whether the stones of the stupendous structure, which stood on the Quirinal behind the Colonna Palace, are those of the Temple of the Sun, erected by Aurelian, or those of a temple dedicated to Jupiter, and built in the first century. All this uncertainty, all these differing suppositions, arise from the want of a proper test by which the age of a Roman building can be accurately ascertained on an examination of its architectural details.

There has always been a certain amount of difficulty in classifying Roman buildings, mainly owing to the fact that there was not that gradual development in the Roman, that has taken place in other styles of architecture. We can attribute the date of a Greek building with considerable accuracy, by an observation of the relative proportions of column and entablature to one another, and we can fix the date of a mediæval building to within fifty years by a com

a In the course of this paper constant reference is made to Mr. Parker's series of Roman Photographs, for without some such illustrations it will be found

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difficult to understand the various changes which took place in the details of Roman architecture.

parison of the profiles of its mouldings; but these styles passed through the usual stages of infancy, maturity, and decay, whereas the Roman architecture, with which we are acquainted-that of the late Republican and Imperial periods (the earlier remains are too slight and imperfect to afford sufficient basis for observations)sprung to full maturity at once, and flourished for two centuries: during this period slight changes in its detail are all we have to guide us in the assignment of a particular building to its true date. It is only by close observation that the almost imperceptible differences which occur can be traced; but by the aid of a few general rules I hope to point out characteristics which distinguish the details of Republican from those of Imperial architecture, and those of the time of Augustus and Trajan from those of Diocletian and Constantine.

It will, however, be desirable first, to consider the origin of Roman art, and it will be necessary also to explain the technical names given to the various members of the orders; for as this book is intended as much for the general reader as for the archaeologist, it is necessary to begin with rudiments, even at the risk of being tedious to the antiquary.

The chief reason why Roman architecture does not shew traces of progress and gradual development is, because it was borrowed bodily from the Greeks, and adapted without much modification to the wants of the Romans. I do not mean to assert for one moment that the Roman is not a distinct style from the Greek. One element in it, however, the order, is certainly common to them both, but its application by the Romans was entirely different from that for which it was originally intended by its inventors, the Greeks, and its combination with the arch gave it an entirely new service to perform. From this combination a novel style resulted, which differs as much in principle from the Greek as the character of the two nations differed. The other element in it, the arch with voussoirs, was borrowed from the Etruscans, and was employed in the oldest constructions of the Kings as early as B.C. 640. This use of the arch, and the dome and vault which are generated from it, is the distinctive mark of the Roman arcuate style, from the Greek trabeate style. A new principle was introduced, then unknown to the Greeks, from which all vaulted buildings, even our Gothic cathedrals, are indirectly derived.

There are so few remains of the Kingly or of the early Republican period, and these are all of such massive character, without ornament, that we are naturally led to the conclusion, that in the early years of Rome the people were too busily employed in con

See Note A, at the end of this Section.

tests with their neighbours, and afterwards in consolidating the State, to have leisure or inclination for the cultivation of decorative architecture. The Romans, the most practical and utilitarian people of history, finding the genius of the Greeks useful to them, long before the extensive intercourse with Greece which followed the Macedonian wars, invited Greek artists to Rome, and, as it would seem, chiefly employed them in their works of architecture. Those of the edifices of the Republican period which have survived Imperial restoration are almost purely Greek in character, and we can trace the work of the "cunning" chisels of the Greek sculptors even on buildings of Imperial times.

It was in the time of Augustus that Roman architecture was reduced to a system by Vitruvius, who after a comparison of the writings of Greek architects, now unfortunately lost, and an observation of their buildings, produced a set of formulæ or receipts, after which temples and other buildings were to be erected: the conventionality he advocated, to an imaginative Greek the enslaving of art, was readily accepted by the practical Roman, who, with no time for invention, preferred erecting his temples according to a fixed law, to trusting to that innate sense of art which has no law, and of which he possessed only a very moderate share.

In order to judge how distinct a style the Roman was from the Greek, let us compare two representative buildings which speak of the opposite characters of the people who produced them :-the Parthenon, and the Colosseum. These edifices, though employed for entirely different purposes, are characteristic of their founders. The Greek had strong religious feelings, and the talent of the greatest artists of the day was devoted to the completion of the shrine of the tutelar divinity of the capital. The Roman, on the contrary, looked upon religion as part of the machinery of the State, useful for giving authority to public acts, and as an instrument to act upon the minds of the populace: his chief passion was for show; he was more proud of an amphitheatre, in which the people could meet by thousands, to be regaled by the spectacle of imperial splendour, and the massacre of the victims of national triumphs, than of the most beautiful temple ever erected. In the Parthenon, every member of the architecture is designed and placed in accordance with certain

For instance, the capitals from the villa of Lucius Verus, Photos. 1497 and 1502, are undoubtedly the works of Greek sculptors; one of these capitals is a counterpart of some that exist at Patras,

and resembles those of the Temple of the Winds at Athens.

d See Note B, at the end of this Section.

ascertained laws of proportion; the guiding mind of the artist is visible in every small detail; nothing was done without a meaning, and to such an extent is refinement carried, that every line in the edifice is curved, in order to fulfil certain laws of optics; in fine, the whole building is calculated to satisfy the tastes of a people of fine perception and high culture. The Colosseum, on the other hand, is a monument of imperial magnificence, on a scale in comparison with which the largest Greek temple would appear diminutive. A fine piece of construction, in which, regardless of the principle which induced the Greek to make the order the full height of his building, order is heaped upon order, and arch vaults over arch, columns are used as buttresses, and entablatures are supported by arches, the stronger upon the weaker, with such a total disregard of former architectural laws, as would make a Greek architect of the time of Pericles shudder: the result, however, is a magnificent edifice, exactly suited to the purpose for which it was intended,-the manifestation of the greatness of imperial Rome, and characteristic of that strongminded people, who made not only the inhabitants but the arts of other nations subservient to their ends.

The chief differences observable in these and other buildings, are that the Greek decorated the constructive parts of the building, while the Roman first constructed the building and then clothed it with ornament. In the first case, the ornament is an essential part of the structure; in the latter, it is an addition. The Parthenon, with its ornaments chiselled off, would be a shapeless mass of stone; but the Baths of Diocletian as they stand, immense piers and walls, with lofty, massive arches and domes, are perhaps as sublime, and certainly speak of the grand people who raised them as forcibly, as when they were lined with marble and covered with stucco ornaments. The chief reason for this distinction between the core of the building and the ornament which covered it, is due to the material and mode of construction. Though in the smaller temples, the walls are built in the Greek fashion called pseudo-isodomos, that is, in unequal courses, with broad slabs and narrow bond-stones of marble, on a backing of peperino, this style of building was not suited for immense buildings like the Thermæ; and where high thick walls and immense vaults were required, brick was found to be a much more suitable material: thus brick and concrete formed the mass of the walls, and the vaults were of brick covered with tiles and overlaid with concrete. Marble must have been too expensive to have been used, even by the wealthy Romans, for the main walls, so this core of brick was adorned externally and internally by slabs