chitecture which are vital, and in which the architectural character, or style, of the building resides. There are others which are more or less superficial and perhaps more or less interchangeable between several styles. The question, therefore, we have to put before ourselves is, Does Santa Sophia represent the Byzantine style by the traits which are essential in its own structure, or are these essential traits those in which it stands alone and does it represent the style rather in accidents and details? On the answer to such a question the place of the church in the history of architecture must depend.

The main characteristic of the Greek genius--namely, its strict adherence to a logical principle and its assiduity in lopping away all such superfluities and inconsistencies as might hamper the expression of such a principle-this characteristic, so obvious in its effects all through Greek literature and Greek art, is particularly obvious in Greek architecture. The supreme achievement of this architecture, to the perfecting of which centuries of careful thought and calculation had been devoted, was the Doric Temple, and the Doric Temple was an exemplification of the resources of a single primary structural principle, the principle of the post and lintel, or upright pillar supporting transverse blocks. This is the simplest, the oldest and the most universal of all building principles, but yet the latent logic in it had never been developed into full expression prior to the evolution of the Doric style. Far from exhibiting this principle to advantage, the sausage-shaped columns and squat, ponderous entablatures of the Nile Temples do but hamper and conceal it. It is impossible to form the least idea of the carrying power of such columns as these, columns which terminate in a suddenly reduced and rounded base at one end,

and in an immense, corpulent bud or flower-shaped capital at the other; nor is it possible to conjecture the proportionate dimensions of the weight the columns carry disguised under the coarse and shapeless forms which compose the entablature. Thousands of years of practice and repetition had left the lintel principle entirely inarticulate in Egyptian hands. It lay hid somewhere under a sort of adipose tissue of superfluous stone, which it was essential to remove if the principle itself were to be brought to light.

This operation was undertaken by the Greeks. Exactly defined, every outline as sharp as if cut out of crystal, every ounce of superfluous material pared away, every form in the structure expressly adapted to its proper function, the Greek temple exhibits the greatest of all structural principles to the utmost possible advantage. The sense of relative proportion between support and burden which is veiled in the Egyptian temple under the gross and inappropriate shapes of the forms employed, is developed in the Greek with exquisite refinement. The column, with sharp-edged flutes, and elastic, vigorous form, is the very embodiment of the idea of easy and powerful support, while the crisply defined entablature is so proportioned as to employ and justify all the strength of the columns without for a moment oppressing it. It is quite evident that the Greeks have here grasped the principle they are dealing with, not as a fact merely, but as an idea. They do not, I mean, stick, where the Egyptian stuck, at the mere convenience of a certain means of support, but go on to exhibit the effectiveness and the logical sufficiency of this means of support, dwelling on it for its own sake, and drawing out all the expressiveness latent in it. In this way they have Inade themselves the spokesmen of a natural idea and are at the head of a

main body of architectural work that goes back through the ages. All that made the action of the builders of Stonehenge right and reasonable when they crossed their huge monoliths, all that makes the action of any farm hand to-day right and reasonable when he knocks up a cowshed in the corner of a field-in short, all there is eternally logical in the post and lintel principle of construction the Doric temple utters once for all with supreme felicity.

Such was the characteristically logical action of the Greeks in the days of trabeated or lintel architecture. Let us come down now to the next age and to the introduction of a new principle, new at least in the dominating position assigned to it in the architecture it appeared in. A people of drains, of bridges, of aqueducts, the arch suited admirably the utilitarian instincts of the Romans. But yet, though they made this feature their own and spread it through the Empire, the Romans never developed its full possibilities or appreciated it as a principle at all. The large and harmonious results and consequent æsthetic significance which a great structural motive, loyally adhered to and permitted to develop its own nature, might achieve, were never grasped by them or understood. For the purposes of construction they for the most part used the arch, but they used it without freedom and without completeness; while for the addition of æsthetic significance they had recourse, without in the least comprehending its real value, to that earlier and simpler principle of which the Greek treatment had so enormously enhanced the prestige.

But these two principles, the arch and the lintel, are, as it is scarcely necessary to point out, incompatible with and destructive of each other. They do their work in different ways, the one by diffusing and spreading the pressure of the superincumbent weight, the other by meeting

it direct; and no combination between them is therefore possible. None the less in Roman work they constantly are combined, or rather they are constantly employed in the same buildings to each other's mutual discomfiture. The arch and vault usually do the real supporting, and columns and entablatures are lacquered over the façade as an afterthought to supply the artistic finish.

The effect of this unnatural coalition was to turn lintel construction into a mere unmeaning decorative detail and to stunt and thwart the development of arched construction altogether. It is with the second of these effects that we are here concerned. It is not, I believe, sufficiently realized by the large number of people who conceive of Roman architecture as the great opportunity of arched construction how essentially second rate all Roman arched construction is. Roman architecture daunts us by sheer size and strength, by the endurance of its iron concrete and the insolent display of its brilliant and showy decoration; and seeing that it stands for Rome's might. majesty and dominion, we are apt to forget that it stands no less incontestably for Rome's lack of lucidity and logic, for Rome's dullness of inward vision and vulgarity of soul. The truth is, of all this tremendous architectural accumulation there is not a building extant which can be called a genuine architectural success; for by a genuine architectural success we imply. I suppose, the working out of some great structural motive or principle in such a way, so completely and freely and disinterestedly, that so long as the principle itself applies to the affairs of men this building in which its properties are exhibited to such advantage shall, for its idea's sake, be welcome and acceptable also. Rome had a great principle to go on, but to express it freely and disinterestedly was beyond

of this surmise he quotes the report of Zosimus that Constantine erected a shrine to the Dioscuri in the Hippodrome and that various other temples dedicated to pagan divinities existed. "A whole population of bronze and marble statues was brought together from Greece, Asia Minor and Sicily. The baths of Zeuxippus alone are said to have had more than sixty bronze statues; a still greater number were assembled in the Augusteum and other squares, and in the Hippodrome, where, according to Zosimus, Constantine placed the Pythian tripod which had been the central object in the temple of Apollo at Delphi." Classic associations and traditions were in short transplanted in full vigor to the new capital. Justinian himself was a typical imperial ruler with all the imperial passion for pomp and display. His own colossal statue in bronze graced the Hippodrome; the baths he had given to the city were among its most splendid adornments, and every city in his dominion was enriched during his reign with important architectural additions. A second Augustus, intensely proud of his office and conscious of its transmitted majesty, nothing could have been more utterly reremoved from his thoughts than the idea of a breach of any kind with the spirit of classic imperialism. Nor was there in popular life any tendency to such a breach. Thanks to the essentially tolerant nature of paganism, the new religion came in on the whole quietly and amicably. It entered forthwith into an inheritance of artistic and architectural remains, as vast in extent as they were doubtful in quality, which it proceeded to turn to its own uses and requirements, nor, on the part of the people any more than on that of the Emperor, was there any desire to repudiate the ideas and arts of their forefathers.

Bearing these facts in mind, we shall

the better understand the problem set before Anthemius by the Emperor. There was certainly no question of striking out a new line, or breaking with the past. The architect found certain time-honored structural theories in being, and in these he had to work. His task was one of adaptation. At the same time the occasion is one of extraordinary interest; for an opportunity was thus offered for a formal criticism, pronounced now for the first time, by the Greek genius upon Roman architecture. Whether there had been earlier indications what that criticism was to be, whether Santa Sophia had its heralds, is a point on which critics still dispute. They have, in any case, almost entirely disappeared, and Santa Sophia, the greatest architectural effort of its age, the work of Greek architects in a Greek city, is the first example of an emancipated, freely spoken Greek judgment on the structural ideas of the Roman era. Standing at the close of that era, it sums up the problem it had dealt with and propounds its own solution.

What that solution was a glance at the great church itself is sufficient to indicate. The plan of Santa Sophia is approximately a square of 250 feet by 225, of which the central portion, 106 feet by 200, is open from the floor to the roof. The noble sense of spaciousness, which is the prevailing impres sion here present, is, however, attained, not merely by the amplitude of the proportions, but by the rhythmical sequence and evolution of the great unfolding curves of the vaulting. These rise in degrees of small supporting domes, semi-domes and segments of domes, until they culminate in the "deep-bosomed" central dome, as Procopius calls it, of 107 feet span, which sweeps with incomparable boldness and freedom across the central area of the building. All who have ever visited the church have been