ROMAN ARCHITECTURE:LAND AND PEOPLE, GREEK INFLUENCE

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CHAPTER VIII.

ROMAN ARCHITECTURE.

BOOKS RECOMMENDED: As before, Anderson and Spiers, Baumeister, Reber. Choisy,

L'Art de bâtir chez les Romains. Desgodetz, Rome in her Ancient Grandeur. Durm, Die

Baukunst der Etrusker; Die Baukunst der Romer. Lanciani, Ancient Rome in the Light

of Modern Discovery; New Tales of Old Rome; Ruins and Excavations of Ancient Rome.

De Martha, Archéologie étrusque et romaine. Middleton, Ancient Rome in 1888.

LAND AND PEOPLE. The geographical position of Italy conferred upon her special

and obvious advantages for taking up and carrying northward and westward the arts

of civilization. A scarcity of good harbors was the only drawback amid the blessings

of a glorious climate, fertile soil, varied scenery, and rich material resources. From a

remote antiquity Dorian colonists had occupied the southern portion and the island

of Sicily, enriching them with splendid monuments of Doric art; and Phoenician

commerce had brought thither the products of Oriental art and industry. The

foundation of Rome in 753 B.C. established the nucleus about which the sundry

populations of Italy were to crystallize into the Roman nation, under the dominating

influence of the Latin element. Later on, the absorption of the conquered Etruscans

added to this composite people a race of builders and engineers, as yet rude and

uncouth in their art, but destined to become a powerful factor in developing the new

architecture that was to spring from the contact of the practical Romans with the

noble art of the Greek centres.

GENERAL CHARACTERISTICS. While the Greeks bequeathed to posterity the most

perfect models of form in literary and plastic art, it was reserved for the Romans to

work out the applications of these to every-day material life. The Romans were above

all things a practical people. Their consummate skill as organizers is manifest in the

marvellous administrative institutions of their government, under which they united

the most distant and diverse nationalities. Seemingly deficient in culture, they were

yet able to recast the forms of Greek architecture in new moulds, and to evolve

therefrom a mighty architecture adapted to wholly novel conditions. They brought

engineering into the service of architecture, which they fitted to the varied

requirements of government, public amusement, private luxury, and the common

comfort. They covered the antique world with arches and amphitheatres, with villas,

baths, basilicas, and temples, all bearing the unmistakable impress of Rome, though

wrought by artists and artisans of divers races. Only an extraordinary genius for

organization could have accomplished such results.

The architects of Rome marvellously extended the range of their art, and gave it a

flexibility by which it accommodated itself to the widest variety of materials and

conditions. They made the arch and vault the basis of their system of design,

employing them on a scale previously undreamed of, and in combinations of

surpassing richness and majesty. They systematized their methods of construction so

that soldiers and barbarians could execute the rough mass of their buildings, and

formulated the designing of the decorative details so that artisans of moderate skill

could execute them with good effect. They carried the principle of repetition of

motives to its utmost limit, and sought to counteract any resulting monotony by the

scale and splendor of the design. Above all they developed planning into a fine art,

displaying their genius in a wonderful variety of combinations and in an unfailing

sense of the demands of constructive propriety, practical convenience, and artistic

effect. Where Egyptian or Greek architecture shows one type of plan, the Roman

shows a score.

FIG. 42.--ROMAN DORIC ORDER. (THEATRE OF MARCELLUS).

GREEK INFLUENCE. Previous to the closing years of the Republic the Romans had

no art but the Etruscan. The few buildings of importance they possessed were of

Etruscan design and workmanship, excepting a small number built by Greek hands.

It was not until the Empire that Roman architecture took on a truly national form.

True Roman architecture is essentially imperial. The change from the primitive

Etruscan style to the splendors of the imperial age was due to the conquest of the

Greek states. Not only did the Greek campaigns enrich Rome with an unprecedented

wealth of artistic spoils; they also brought into Italy hosts of Greek artists, and filled

the minds of the campaigners with the ambition to realize in their own dominions the

marble colonnades, the temples, theatres, and propylæa of the Greek cities they had

pillaged. The Greek orders were adopted, altered, and applied to arcaded designs as

well as to peristyles and other open colonnades. The marriage of the column and arch

gave birth to a system of forms as characteristic of Roman architecture as the Doric

or Ionic colonnade is of the Greek.

THE ROMAN ORDERS. To meet the demands of Roman taste the Etruscan column

was retained with its simple entablature; the Doric and Ionic were adopted in a

modified form; the Corinthian was developed into a complete and independent order,

and the Composite was added to the list. A regular system of proportions for all

these five orders was gradually evolved, and the mouldings were profiled with arcs of

circles instead of the subtler Greek curves. In the building of many-storied structures

the orders were superposed, the more slender over the sturdier, in an orderly and

graded succession. The immense extent and number of the Roman buildings, the

coarse materials often used, the relative scarcity of highly trained artisans, and above

all, the necessity of making a given amount of artistic design serve for the largest

possible amount of architecture, combined to direct the designing of detail into

uniform channels. Thus in time was established a sort of canon of proportions, which

was reduced to rules by Vitruvius, and revived in much more detailed and precise

form by Vignola in the sixteenth century.

FIG. 43.--ROMAN IONIC ORDER.

In each of the orders, including the Doric, the column was given a base one half of a

diameter in height (the unit of measurement being the diameter of the lower part of

the shaft, the crassitudo of Vitruvius). The shaft was made to contract about one-

sixth in diameter toward the capital, under which it was terminated by an astragal or

collar of small mouldings; at the base it ended in a slight flare and fillet called the

cincture. The entablature was in all cases given not far from one quarter the height of

the whole column. The Tuscan order was a rudimentary or Etruscan Doric with a

column seven diameters high and a simple entablature without triglyphs, mutules, or

dentils. But few examples of its use are known. The Doric (Fig. 42) retained the

triglyphs and metopes, the mutules and guttæ of the Greek; but the column was

made eight diameters high, he shaft was smooth or had deep flutings separated by

narrow fillets, and was usually provided with a simple moulded base on a square

plinth. Mutules were used only over the triglyphs, and were even replaced in some

cases by dentils; the corona was made lighter than the Greek, and a cymatium

replaced the antefixæ on the lateral cornices. The Ionic underwent fewer changes,

and these principally in the smaller mouldings and details of the capital. The column

was nine diameters high (Fig. 43). The Corinthian was made into an independent

order by the designing of a special base of small tori and scotiæ, and by sumptuously

carved modillions or brackets enriching the cornice and supporting the corona above

a denticulated bed-mould (Fig. 44). Though the first designers of the modillion were

probably Greeks, it must, nevertheless, be taken as really a Roman device, worthily

completing the essentially Roman Corinthian order. The Composite was formed by

combining into one capital portions of the Ionic and Corinthian, and giving to it a

simplified form of the Corinthian cornice. The Corinthian order remained, however,

the favorite order of Roman architecture.

FIG. 44.--CORINTHIAN ORDER (TEMPLE OF CASTOR AND POLLUX).

USE OF THE ORDERS. The Romans introduced many innovations in the general use

and treatment of the orders. Monolithic shafts were preferred to those built up of

superposed drums. The fluting was omitted on these, and when hard and semi-

precious stone like porphyry or verd-antique was the material, it was highly polished

to bring out its color. These polished monoliths were often of great size, and they

were used in almost incredible numbers.

Another radical departure from Greek usage was the mounting of columns on

pedestals to secure greater height without increasing the size of the column and its

entablature. The Greek anta was developed into the Roman pilaster or flattened wall-

column, and every free column, or range of columns perpendicular to the façade, had

its corresponding pilaster to support the wall-end of the architrave. But the most

radical innovation was the general use of engaged columns as wall-decorations or

buttresses. The engaged column projected from the wall by more than half its

diameter, and was built up with the wall as a part of its substance (Fig. 45). The

entablature was in many cases advanced only over the columns, between which it

was set back almost to the plane of the wall. This practice is open to the obvious

criticism that it makes the column appear superfluous by depriving it of its function

of supporting the continuous entablature. The objection has less weight when the

projecting entablature over the column serves as a pedestal for a statue or similar

object, which restores to the column its function as a support (see the Arch of

Constantine, Fig. 63).

FIG. 45.--ROMAN ARCADE WITH ENGAGED COLUMNS

(From the Colosseum.)

ARCADES. The orders, though probably at first used only as free supports in

porticos and colonnades, were early applied as decorations to arcaded structures.

This practice became general with the multiplication of many-storied arcades like

those of the amphitheatres, the engaged columns being set between the arches as

buttresses, supporting entablatures which marked the divisions into stories (Fig. 45).

This combination has been assailed as a false and illogical device, but the criticism

proceeds from a too narrow conception of architectural propriety. It is defensible

upon both artistic and logical grounds; for it not only furnishes a most desirable play

of light and shade and a pleasing contrast of rectangular and curved lines, but by

emphasizing the constructive divisions and elements of the building and the vertical

support of the piers, it also contributes to the expressiveness and vigor of the design.

VAULTING. The Romans substituted vaulting in brick, concrete, or masonry for

wooden ceilings wherever possible, both in public and private edifices. The Etruscans

were the first vault-builders, and the Cloaca Maxima, the great sewer of Republican

Rome (about 500 B.C.) still remains as a monument of their engineering skill.

Probably not only Etruscan engineers (whose traditions were perhaps derived from

Asiatic sources in the remote past), but Asiatic builders also from conquered eastern

provinces, were engaged together in the development of the wonderful system of

vaulted construction to which Roman architecture so largely owed its grandeur.

Three types of vault were commonly used: the barrel-vault, the groined or four-part

vault, and the dome.

FIG. 46.--BARREL VAULT.

The barrel vault (Fig. 46) was generally semi-cylindrical in section, and was used to

cover corridors and oblong halls, like the temple-cellas, or was bent around a curve,

as in amphitheatre passages.

FIG. 47.--GROINED VAULT.

g, g, Groins.

The groined vault is formed by the intersection of two barrel-vaults (Fig. 47). When

several compartments of groined vaulting are placed together over an oblong plan,

a double advantage is secured. Lateral windows can be carried up to the full height

of the vaulting instead of being stopped below its springing; and the weight and

thrust of the vaulting are concentrated upon a number of isolated points instead of

being exerted along the whole extent of the side walls, as with the barrel-vault. The

Romans saw that it was sufficient to dispose the masonry at these points in masses

at right angles to the length of the hall, to best resist the lateral thrust of the vault.

This appears clearly in the plan of the Basilica of Constantine (Fig. 58).

The dome was in almost all Roman examples supported on a circular wall built up

from the ground, as in the Pantheon (Fig. 54). The pendentive dome, sustained by

four or eight arches over a square or octagonal plan, is not found in true Roman

buildings.

The Romans made of the vault something more than a mere constructive device. It

became in their hands an element of interior effect at least equally important with

the arch and column. No style of architecture has ever evolved nobler forms of

ceiling than the groined vault and the dome. Moreover, the use of vaulting made

possible effects of unencumbered spaciousness and amplitude which could never be

compassed by any combination of piers and columns. It also assured to the Roman

monuments a duration and a freedom from danger of destruction by fire impossible

with any wooden-roofed architecture, however noble its form or careful its execution.

CONSTRUCTION. The constructive methods of the Romans varied with the

conditions and resources of different provinces, but were everywhere dominated by

the same practical spirit. Their vaulted architecture demanded for the support of its

enormous weights and for resistance to its disruptive thrusts, piers and buttresses of

great mass. To construct these wholly of cut stone appeared preposterous and

wasteful to the Roman. Italy abounds in clay, lime, and a volcanic product, pozzolana

(from Puteoli or Pozzuoli, where it has always been obtained in large quantities),

which makes an admirable hydraulic cement. With these materials it was possible to

employ unskilled labor for the great bulk of this massive masonry, and to erect with

the greatest rapidity and in the most economical manner those stupendous piles

which, even in their ruin, excite the admiration of every beholder.

FIG. 48.--ROMAN WALL MASONRY.

a, Brickwork; b, Tufa ashlar; r, Opus reticulatum; i, Opus incertum.

STONE, CONCRETE, AND BRICK MASONRY. For buildings of an externally

decorative character such as temples, arches of triumph, and amphitheatres, as well

as in all places where brick and concrete were not easily obtained, stone was

employed. The walls were built by laying up the inner and outer faces in ashlar or

cut stone, and filling in the intermediate space with rubble (random masonry of

uncut stone) laid up in cement, or with concrete of broken stone and cement dumped

into the space in successive layers. The cement converted the whole into a

conglomerate closely united with the face-masonry. In Syria and Egypt the local

preference for stones of enormous size was gratified, and even surpassed, as in

Herod's terrace-walls for the temple at Jerusalem, and in the splendid structures of

Palmyra and Baalbec. In Italy, however, stones of moderate size were preferred, and

when blocks of unusual dimensions occur, they are in many cases marked with false

joints, dividing them into apparently smaller blocks, lest they should dwarf the

building by their large scale. The general use in the Augustan period of marble for a

decorative lining or wainscot in interiors led in time to the objectionable practice of

coating buildings of concrete with an apparel of sham marble masonry, by carving

false joints upon an external veneer of thin slabs of that material. Ordinary concrete

walls were frequently faced with small blocks of tufa, called, according to the manner

of its application, opus reticulatum, opus incertum, opus spicatum, etc. (Fig. 48). In

most cases, however, the facing was of carefully executed brickwork, covered

sometimes by a coating of stucco. The bricks were large, measuring from one to two

feet square where used for quoins or arches, but triangular where they served only as

facings. Bricks were also used in the construction of skeleton ribs for concrete vaults

of large span.

VAULTING. Here, as in the wall-masonry, economy and common sense devised

methods extremely simple for accomplishing vast designs. While the smaller vaults

were, so to speak, cast in concrete upon moulds made of rough boards, the enormous

weight of the larger vaults precluded their being supported, while drying or

"setting," upon timber centrings built up from the ground. Accordingly, a skeleton of

light ribs was first built on wooden centrings, and these ribs, when firmly "set,"

became themselves supports for intermediate centrings on which to cast the concrete

fillings between the ribs. The whole vault, once hardened, formed really a monolithic

curved lintel, exerting no thrust whatever, so that the extraordinary precautions

against lateral disruption practised by the Romans were, in fact, in many cases quite

superfluous.

DECORATION. The temple of Castor and Pollux in the Forum (long miscalled the

temple of Jupiter Stator), is a typical example of Roman architectural decoration, in

which richness was preferred to the subtler refinements of design (see Fig. 44). The

splendid figure-sculpture which adorned the Greek monuments would have been

inappropriate on the theatres and thermæ of Rome or the provinces, even had there

been the taste or the skill to produce it. Conventional carved ornament was

substituted in its place, and developed into a splendid system of highly decorative

forms. Two principal elements appear in this decoration--the acanthus-leaf, as the

basis of a whole series of wonderfully varied motives; and symbolism, represented

principally by what are technically termed grotesques--incongruous combinations of

natural forms, as when an infant's body terminates in a bunch of foliage (Fig. 49).

Only to a limited extent do we find true sculpture employed as decoration, and that

mainly for triumphal arches or memorial columns.

FIG. 49--ROMAN CARVED ORNAMENT.

(Lateran Museum.)

The architectural mouldings were nearly always carved, the Greek water-leaf and egg-

and-dart forming the basis of most of the enrichments; but these were greatly

elaborated and treated with more minute detail than the Greek prototypes. Friezes

and bands were commonly ornamented with the foliated scroll or rinceau

(a convenient French term for which we have no equivalent). This motive was as

characteristic of Roman art as the anthemion was of the Greek. It consists of a

continuous stem throwing out alternately on either side branches which curl into

spirals and are richly adorned with rosettes, acanthus-leaves, scrolls, tendrils, and

blossoms. In the best examples the detail was modelled with great care and

minuteness, and the motive itself was treated with extraordinary variety and fertility

of invention. A derived and enriched form of the anthemion was sometimes used for

bands and friezes; and grotesques, dolphins, griffins, infant genii, wreaths, festoons,

ribbons, eagles, and masks are also common features in Roman relief carving.

The Romans made great use of panelling and of moulded plaster in their interior

decoration, especially for ceilings. The panelling of domes and vaults was usually

roughly shaped in their first construction and finished afterward in stucco with rich

moulding and rosettes. The panels were not always square or rectangular, as in

Greek ceilings, but of various geometric forms in pleasing combinations (Fig. 50). In

works of a small scale the panels and decorations were wrought in relief in a heavy

coating of plaster applied to the finished structure, and these stucco reliefs are

among the most refined and charming products of Roman art. (Baths of Titus; Baths

at Pompeii; Palace of the Cæsars and tombs at Rome.)

FIG. 50.--ROMAN CEILING PANELS.

(a, From Palmyra; b, Basilica of Constantine.)

COLOR DECORATION. Plaster was also used as a ground for painting, executed in

distemper or by the encaustic process, wax liquefied by a hot iron being the medium

for applying the color in the latter case. Pompeii and Herculaneum furnish countless

examples of brilliant wall-painting in which strong primary colors form the ground,

and a semi-naturalistic, semi-fantastic representation of figures, architecture and

landscape is mingled with festoons, vines, and purely conventional ornament. Mosaic

was also employed to decorate floors and wall-spaces, and sometimes for ceilings.13

The later imperial baths and palaces were especially rich in mosaic of the kind called

opus Grecanicum, executed with numberless minute cubes of stone or glass, as in the

Baths of Caracalla and the Villa of Hadrian at Tivoli.

To the walls of monumental interiors, such as temples, basilicas, and thermæ,

splendor of color was given by veneering them with thin slabs of rare and richly

colored marble. No limit seems to have been placed upon the costliness or amount of

these precious materials. Byzantine architecture borrowed from this practice its

system of interior color decoration.

13. See Van Dyke's History of Paintings, p. 33.

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