The Church of Sancta Sophia, Constantinople: A Study of Byzantine Building

by W. R. Lethaby; Harold Swainson

CHAPTER VIII

FOSSATI’S REPARATIONS. SALZENBERG’S DESCRIPTION.

Sancta Sophia seems really to have been in a dangerous condition when, in 1847, the Sultan Abdul Mesjid began a much-needed work of reparation which was carried on under the guidance of the Italian architect Fossati, who appears to have taken great pains, and notwithstanding some alterations and “restorations” in the worst sense he deserves our gratitude for probably saving the building. In the preface to his lithograph views published in London in 1852 he says, “The portions of the building that looked most threatening were reconstructed, and the lead roofs were repaired. The dome was relieved of four heavy buttress arches, whose function was taken by a double ceincture of iron around its base. Thirteen columns of the gynaeceum, which were inclining under the thrust of the great arches that support the dome, were put straight again.” The marble work of the interior was cleaned, and the gold mosaic vaults were cleared of the crust of limewash which concealed them. All representations of figures were however covered again. The sultan’s tribune was built, Fossati says, “in the Byzantine style.” The walls outside, after being repaired, were covered with a coating of plaster on which red stripes were painted.

Since this time various remains of the Great Court, which existed as late as 1873, have entirely disappeared, and the broad bare space, in front of the exonarthex, has little now to recall the atrium with its fountain and quadriporticus.

All study of the church in its condition at that time must be based on the exhaustive plates and text of Salzenberg.[235] M. Texier had in 1834 made some drawings at Constantinople, which are now preserved in the library of the Royal Institute of Architects; and several coincidences seem to point to Salzenberg’s having had the use of Texier’s ground plan. In any case Texier was the first to make correct plans including the upper floor, also the atrium, baptistery, and the circular building at the north-east. As Salzenberg made full use of the unique opportunity afforded by the scaffolding, when the building was given over to the workmen, we have thought it wise to give a condensed paraphrase of his account where it is descriptive of the structure, even at the risk of some repetition. Our remarks in other places where they may overlap are the result of our own observation, from different points of view. The rest of this chapter is an abridgment of Salzenberg’s text and descriptive of his plates, and we add nothing unless in notes or square brackets.

Design.—The exterior walls of the atrium, with several entrances, were built of brick, but the inner sides had marble columns between square brick piers, two columns to one pier. These carried semicircular arches. The atrium walks, as remains showed, were barrel-vaulted, and the vaults were formerly covered with mosaic. The parts for which there was evidence remaining are shown in darker hatching in Salzenberg’s plate vi. The outer wall on the north side, with several arched openings; and traces of the western boundary still existed.

The long vestibule in front of the narthex has groined vaulting, and large windows in its west wall; there are some Turkish additions to this part. A door from each lateral cloister, and two others from the open atrium, led into it. On either side of the two doors from the court are strong projecting piers, connected above by a wide arch, forming a porch-like shelter over the doors. These four piers rise above the roof of the vestibule.[236]

Double tiers of buttress arches spring from each of these piers to the west wall of the church. A close examination of the wall and piers led to the conviction that they are not contemporary with the church, but were built later, though partly of old material.[237] The upper cornices for instance differ. [Modifications here can be explained by removal of Bell Tower, see p. [194].] The piers were probably erected by Byzantine builders, to strengthen the western vault.

Five doors lead to the narthex, the windows of which are above the roof of the outer vestibule. The walls are covered with marble, and the vaulting with mosaic; while the walls and ceiling of the exonarthex, are quite plain. Two other doors enter the narthex at its north and south ends, and nine lead from it into the church; the large central entrance being the Royal Door.

The walls of the church form approximately a square, the length of which in the interior, exclusive of the apse, is 241 feet, and the breadth 224.[238]

The dome measures 100 feet across from the edge of the cornice, but above the cornice the vaulted space is 104 feet across; it is 179 feet from the floor to the vertex. The dome rises above the square area on four huge arches, with a large semidome to the east and another to the west, each of which embraces three smaller spans. The lateral openings which thus pierce the east and western semidomes are covered by conchs, but the middle opening in each case has a cylindrical vault, that to the east being prolonged into the eastern apse.

At the corners of the central square of the nave rise four large piers, which are joined by arches to four buttress piers in the northern and southern walls behind them. The arched openings connect the three parts into which the aisles are divided by the piers. On either side of each of the central openings from the eastern and western hemicycles rise other piers, which are pierced by narrow arched passages, running from north to south. The piers, eight altogether, carry the whole vaulting of the nave, as well as a part of that of the side aisles. Between the middle division of each aisle and the nave are four large columns with five arches on the ground floor, and on the first floor six smaller columns with seven arches. Above again is a wall with windows, filling up the great arches on the north and south sides under the dome. Each exedra has, on the ground floor, two large columns with three arches, and, on the floor above, six small columns with seven arches.

The vault of each division of the aisles is supported on four columns. Those next the east and west walls of the church, eight in all, are square, the others are round. The divisions of the galleries follow those of the aisles underneath. The four main piers however were pierced by additional arched openings [now filled up] between the galleries and the nave. The part over the narthex opens to the nave by three arches, on coupled columns. Above is the immense semicircular window which fills up the central barrel vault at the western end.

All the openings towards the nave in the upper aisles have marble parapets. The vaulting of the lower aisles rests on forty round columns and eight square ones, and in the galleries on sixty round columns, not including the coupled columns at the west; this makes in all a hundred round columns. Possibly the eight square pillars in the aisles were employed, so that this number should not be exceeded.

In the walls are numerous large windows, and the dome is pierced by forty just above the cornice; thus light streams into the church from every quarter. Much of the dome, including the central circle of mosaic at the crown, can be seen from the Royal Door.

The greater number of the buildings which formerly surrounded the church are either destroyed, or so altered by Turkish minarets and buttresses that it is difficult to conjecture their original form.[239]

On the north and south of the narthex are long porches of Byzantine workmanship, with cylindrical vaults. In the northern one is a flight of fourteen steps leading down from outside to the narthex. The southern porch is called by Von Hammer the Vestibule of the Warriors. It is mentioned by Nicetas as the place where the Archangel Michael was represented in mosaic. It was through this porch that the emperor passed to the church, and here some of the bodyguard would remain. The vaulting still bears the remains of mosaics which are now covered up.

On the east sides of both the northern and southern porches are accesses to the gynaeceum, formed of a series of inclined planes. The entrance to the northern one is from the porch, but the southern stair is reached from a narrow passage between it and the baptistery. To the west of the northern and southern porches, in the angles between them and the outside walls of the atrium, are the two minarets built by Murad III.

On the first-floor level, above the southern porch and part of the adjacent staircase, is a series of chambers,[240] of which the purpose is not known. The walls of the two larger chambers are covered with marble, and their ceilings with mosaic.

Only one stairway is now extant at the east. The minaret built by Mahomed II., which helps to buttress the south-east corner of the church, occupies the position of a second. Salzenberg’s Plate xiv. shows the stairway restored, but in Plate xiii. the northern one is removed to explain the arrangement of the part of the building to the south of it. On entering at the door of this north-eastern stairway one can either mount the ascending planes which wind round a well for light, or go to the left through a small lobby into the church. On the right steps ascend to the round building adjacent. The light ‘well’ once ascended the whole height of the staircase, which seems to have been formerly still higher, as the eastern wall of the church, which is here prolonged northwards, rises about four feet above the present roof of the stairway, and shows the remains of a window. These stairways may have been built by Andronicus Palaeologus in the fourteenth century, when he erected the buttress masses which are called pyramids by Nicephorus Gregoras. All these stairways however were additions to the building, probably built when the dome abutments were strengthened. The original staircases to the gynaeceum were in the four piers by the northern and southern walls of the church, and the steps from the gynaeceum to the base of the dome still remain.[241]

In the eastern buttress pier on the south side is a portion of one of the original staircases, leading downwards from the gynaeceum, though beneath on the ground floor there is now a vaulted passage.[242] In the western buttress pier on the south side, at the ground-floor level, is a vaulted passage adorned with mosaic, and a door leading to an external addition. In the similar position on the gynaeceum level, the staircase, which formerly led higher, has been destroyed, to make a way to the upper floor of this same late annex.

The south-east porch may have been used by the emperors on non-festal days, as it was close to the southern aisle where they sat. Three columns are now placed on each side of this porch; the two outer ones are of porphyry, and have capitals with a design of a basket and doves.[243] These capitals are fine Byzantine work, although the arch above may be Turkish. Here seven steps descend into the church. The other porch on the north of the east end was destroyed at the last restoration to make an entrance for the Sultan. Remains of a series of chambers can still be traced on the east side between the porches: their roofs must have been below the lower windows of the eastern wall. The chambers are now built up; but their original plan may be conjectured from the lead saddle-roofs, which have gutters that conduct the rainwater through the outer wall. Two doors from the porches, and two doors from the church—all four now blocked up—show the previous communication with this row of chambers, which probably contained the priests’ vestments, and the vessels for the altar.

Amongst the buildings that surrounded the church must be mentioned the skeuophylakium, in which was kept the sacred furniture. Here were placed biers for the state funerals: conspicuous amongst them was one quite covered with gold, the gift of Studios and Stephanos. This probably was the isolated round building at the north-east of the church, reached by the steps previously mentioned. It now has two floors of wood; for security there were no windows, but only twelve niches in the wall, in one of which is the door. This building now serves as a storehouse for the army kitchen (imareh) adjacent, and is much injured. Windows have been made in the walls, and the door altered.[244] The baptistery [south-west building] is square outside, but octagonal with four niches within. It is vaulted by a dome without ribs. On the east side is an apse, and on the west a porch. The Anonymous says that the baptistery was formerly called the Chapel of S. John, and that it was built by Justinian. [Entrance to this is now obtained by a door, which has been pierced in its north-eastern angle. The western wall has a semicircular-headed opening, of the same size as the niches, leading to a narthex or vestibule to which there is now no access from the outside.]

In addition to the western entrance, a door on the north, now blocked up, led through an open porch into a small court. The large cylindrical arch of this porch had a screen at its northern side, the columns and door-frame[245] of which are still extant, but the marble lattice is destroyed. Through an arch in the east wall of this porch the addition which was made outside the south-west buttress pier could be reached, where there was a passage into the church. Salzenberg’s plan[246] of this addition is taken at the level of a landing reached by a staircase from the passage through the south-west buttress pier. This landing seems at one time to have been connected with a chamber above the north porch of the baptistery, and from thence with the stairway at the south-west angle of the church. Leading upwards from this landing is the original staircase to the gynaeceum, and at this level there is a small chapel vaulted with a cupola.[247] The vault is adorned with mosaic; figures of angels stand in the four pendentives. Originally the chapel was not lighted; but at the last “restoration” a hole was made in the roof, which was filled with glass; a passage from this chapel to the gynaeceum is probably Turkish. The chapel is supposed by the Greeks to be the one into which the officiating priest disappeared at the capture by the Turks.

The Turks turned the baptistery into a storeroom for the oil used in lighting the church, but on the sudden death of the Sultan Mustapha I. it was converted into a turbeh. Almost the whole of the church is raised above vaulted cisterns. An opening in the south aisle[248] gives access to the water, and there is another opening in the north-west exedra. The depth of the water prevented a close inspection.

Of the two additions made in Byzantine times to the centre of the north and south walls on the outside, and intended to buttress the aisles, the southern one has been further lengthened by the Turks. To preserve the use of the door and window in the wall of the church, each addition was pierced by a passage. Remains of stairways and side passages have also been found here.[249] Other remains of buildings existed on the north and south sides of the church, but they were too insufficient to base any conclusions on them.

Materials.—The principal materials employed are brick, and a kind of peperino stone. The latter is used in those parts of the building which have to stand great pressure, such as the four large piers in the nave, the piers to east and west, and the extra projections from the buttress piers in the side aisles and gynaeceum. In addition a horizontal course two feet deep runs round the whole building four feet from the floor.

The outside walls of the original building, like the vaulting, were entirely of brick, but in the later additions they are formed of alternate layers of brick and stone, and some of the later buttress masses are almost entirely of stone.

The bricks are as a rule about fourteen inches long and two inches thick; some vaulting bricks brought from the ruins by the porch on the east measured fourteen inches square and two inches thick; on one side of them were scratched lines probably made by the three fingers of the maker, and on the other was an oblong label inclosing an inscription (1); another had a different inscription (2); and a third, not from this vault, but of the same size, was also inscribed (3).

[(1) Reads Constantius or Constantine. (2) May be rendered “the church which is being erected,” by reading a participle of ἐγείρω for the second and third letter. (3) This is also given in the Revue Archéologique, 1876, with some slight differences in second and third lines; it is there said to have been found between SS. Sophia and Irene. It probably reads, “Lord, help Philemon: Indiction 7.” The two first vowels of Philemon have changed places, and the contraction form after “ΙΝΔ” is also turned the wrong way.]

At the base of the dome the bricks are 27 × 9 inches, and two inches thick. Some appear to be twenty-seven inches square; but at the apex of the dome, by the hole intended for the lamp-chain, the thickness is twenty-four inches. There was no trace of the light bricks made in Rhodes which the Anonymous mentions; although in the pendentives a light substance, whitish, with impressions of plants in it, was used in irregular masses. The mortar has a red colour, and was evidently mixed with crushed brick; the joints are from one to two inches thick.

The marble of Proconnesus, which somewhat resembles the architectural marble of Carrara, is employed for the cornices, capitals, and bases of the columns, and for the windows.

In Salzenberg’s plans the materials are expressed by different depths of tint; the darkest being marble, slightly lighter is stone, and a still lighter brickwork; the additional buildings are represented in the lightest tones, and the Turkish buildings with strokes and dots.

Construction.—The outside walls average a height of seventy feet: those on the north and south have a thickness of three and a half feet, that on the east is four and a half feet, and that on the west between the nave and narthex five feet. Where the arches rest on the walls there are piers which project about two feet: thus the west wall, for instance, has in parts a thickness of seven feet. As a general rule, the interior vaults of wide span continue through the walls, and appear as arches on the outside face. The window and door openings are semicircular. The marble finishings were inserted after the completion of the walls.

The dome at first sight seems to rest upon four arches each of 100 feet span; it is, however, only on the east and west that these arches are open. From north to south the main piers are 106 feet apart, and their breadth in this direction is fifteen feet eight inches; but on either side of the nave there are projections, narrowing the opening to 100 feet, and giving the open arches abutments of eighteen feet eight inches.

Behind each of these main piers again, at a distance of twenty-nine and a half feet from them, stands one of the buttress or staircase piers, which, including the outside wall, is seventeen feet four inches by twenty-four and a half feet in area. Round arches, which appear below the vaults, transmit the thrust of the great arches from the main piers to these buttressing piers. Above these each of the immense buttress masses which stand right across the aisles, and rise to within eighteen feet of the springing of the dome, bear upon two relieving arches of different radii, so as not to load the vaulting beneath.[250]

The cylindrical arches, which, at the ground-floor aisles and the gynaeceum, connect the great piers with the outer buttress piers, are each reinforced by two extra arches, standing on stone additions to the main piers, from which they project five feet.[251] These arches, though thus strengthened, are almost all out of shape; those by the two northern main piers have been pushed out nearly fifteen inches.

A drawing given in Salzenberg’s text shows the south arch which supports the dome with the mosaics removed. The piers from east to west are seventy-two feet apart, and accordingly the span of the arch is seventy-two feet, its soffite being fifteen feet eight inches. The arch is five feet deep, formed of two unconnected rings, and on each side the lower part is laid in horizontal courses so that the portion with radiating joints is only three quarters of the whole arch. The window wall which fills the arch opening is four feet thick, and is bonded with the horizontal courses, but a movement of the arches has caused a fissure, which is shown in the diagram. These window walls on the south and north sides have cracked in several places. The upper part of the window wall on the north side is only twenty-nine inches thick. The windows have been reduced and strengthened by inserting stone jambs.

On the north and south side are also two large arches, which project on the inside three feet from the window wall and rest on the main piers, having the same height and span as the arches on the east and west. They complete the square form under the cornice of the dome, and give the idea that the dome is carried on four arches of 100 feet span: whereas in reality, as has just been shown, the real supporting arches on the north and south side are concealed in the window wall, and are not suggested in any way in the interior decoration, being only visible on the outside.[252]

The four principal piers are very carefully built of shaped stones, the joints, according to Procopius, being run with lead, but the Silentiary mentions a cement as being used here.

The height from the floor to the springing of the great arches is seventy-three feet.

The arches of seventy-two feet span have abutments of twenty-four and a half feet, which are increased above the vaults of the gynaeceum to twenty-nine feet.

The great arches under the springing of the dome are about four bricks, or five feet, thick. The depth at the top, including the cornice of the dome, is about six feet and three quarters. The centre of the arches is two and a half feet above the springing, so that they are more than semicircular. In the internal angles formed by them are the four pendentives. The cornice has a projection of about two feet nine inches. The lead mentioned by the Silentiary may be found in the interstices of its stones.

The dome springs from the cornice on forty piers, about three feet five inches broad on the inside, and about eight and a half feet deep in the direction of the radius. They are connected by arches which form windows four feet nine inches wide. On the outside the piers project beyond the arches, and may perhaps at one time have been connected with other arches, forming a drum for the dome: within they form part of the ribs of the dome.

In the interior the ribs project at the springing six inches from the surface of the dome, which is there twenty-nine inches thick, but their projection gradually diminishes, till they are lost in the great circle of thirty-seven and a half feet diameter in the centre. In the interior from rib across to rib is 104 feet, so that all round on the cornice is the passage two feet nine inches wide, which, according to Paulus, was used by the lamp-lighter. The dome rises forty-six feet nine inches above this gangway, so that it is considerably less than a semicircle in section. The original dome, according to Agathias, must have been even flatter. Theophanes states the increase in height to have been twenty feet, and Zonaras twenty-five.[253]

The dome has now many swellings and depressions which are not visible from the ground. At the same time we see how immovable domed vaulting is, if only its supports remain uninjured.

At the east and west ends of the nave the two cylindrical vaults are each forty-seven feet across. They rest on the four lesser piers, and have an abutment of fifteen and a half feet. The four exedras are each forty-one feet across. All the conchs and semidomes have drums outside, which are pierced by the windows. The conchs which cover the exedras have strong arches, where they intersect the semidomes. The weight of the exedra conchs is chiefly supported by the columns; the upper columns of the south-east exedra, at the time of the last restoration, were much inclined, and had to be brought back to the vertical, by propping the arches, cutting away the old bases, and inserting new pieces—the columns being surrounded and supported by wooden cradling. The thickness of the western barrel vault is four feet; the eastern apse is about three feet thick. The western semidome received an additional thickness at the restoration.

Vaulting of the Aisles.—The three principal divisions of each aisle are covered by domical vaults. The vault arches rest partly on columns; and the spaces between these columns and the outside wall are also vaulted. The middle division of the north and south aisles has two domical vaults, separated by a barrel vault that opens towards the nave arches, and to the window in the outside wall. The arches have iron ties four inches thick, which stretch from the outer wall to the columns of the nave, and grip them tightly. The four columns in the aisles which carry the vault are much lower than those between the aisles and nave, and for this reason the narrow vaulted space, which joins the aisle vault to the nave arcade, is formed by a stilted quadrant.

This arrangement only applies to the lower aisles: above is a stilted cylindrical vault, running lengthways between the main gynaeceum vaults, and the arcade towards the nave.[254] Here, besides the iron ties, there are wooden beams.

The large arches in the aisles are twenty-nine and a half feet from column to column. The domical vaulting of the aisles is very flat—a combination of cross groining and a dome. For, though it starts with angles at the four corners, it gradually merges into a dome at the apex. The vaulting bricks are arranged in horizontal circles.[255] A diagonal band of mosaic starts from each corner, and merges into a central circle.[256] In the gynaeceum the vaulting is higher and consists of spherical domes, the radii being half the diagonals of the spaces covered. The mosaic decoration here again follows the form.[257]

Narthex.—The narthex is covered with vaults, similar to those of the lower aisles of the nave. Each vaulted space is separated from the next by a segmental arch, six and a half feet wide with a span of twenty-six and a half feet, which abuts on the west wall of the nave, and the piers of the outer wall. The vault spaces vary from sixteen and a half feet in the middle to thirteen and a half feet towards the ends. The piers of the outer wall are connected together by arches above the window openings, and the spaces below the windows are filled up with thin ‘screen’ walls. The upper floor of the narthex is covered with a semicircular vault, intersected by the window arches between the piers of the outer wall. These piers are the continuation of those beneath, and have a width of six feet, and a depth of seven. They had to bear the thrust of the barrel vault of twenty-six and a half feet span: the buttresses previously mentioned, springing from the piers of the propylaeum, were subsequently added to strengthen them.

In the exonarthex there are cross groins with arches between. The arches have a span of fourteen and a half feet and an abutment of seven feet. This seems to be of a later construction than the rest of the vaulting, and not improbably, as well as the piers, belongs to a reconstruction of this porch, undertaken to strengthen the west wall of the narthex.

All the arches of the nave which stand on columns have iron ties; and to the three large openings of the gynaeceum at the west end of the nave there are wooden binders as well. In the lower rows of windows beneath the dome on both the north and south sides of the nave iron ties can be seen, which seem to stretch across the whole width of the large arches which support the dome.

Roofs.—All the exterior vaults are covered with lead about a quarter of an inch thick, which rests on a layer of wooden battens placed immediately upon the brick vaults. There are several passages and staircases for access to the roofs. Access to the exterior of the side aisles and narthex is gained by the staircases in the buttress piers: the stairs are supported on brick arches. In the north-east pier the stair space is only four feet eight inches by six feet seven inches, and in this are placed the flights of stairs two feet eight inches wide, with a space of fifteen inches between.[258] At the top of each flight spaces are hollowed out in the wall, which serve as landings from one flight to another.

These stairs ascend above the roofs of the side aisles to the upper part of the buttress piers, from which open passages, with breast-walls on either side, lead above the buttress piers to the angles at the base of the dome. There were two flights of steps leading to the platform of the dome: one of these on the south-east, which Salzenberg shows dotted in Plate viii., is still quite preserved, though injured at the upper end; remains too can still be traced of the north-west stair. A door now built up, on the north side of the south-east stair, and remains of vaulting in the north-west stair, seem to show that other passages must have existed.

The roof of the cylindrical vaulting at the west end of the nave is reached by means of stairs in the small round towers, which flank it on the outside.[259] These turrets can also be reached from the roof of the narthex. Another passage runs along under the narthex roof at the west (Salz., Plate ix.), which has an opening close to the upper surface of the vaulting, and from thence any part above the nave can be reached. Probably this was formerly used for the lighting of the church. To reach the cornice at the foot of the dome there was an opening in the wall under one of the dome windows.

Decorative Work.—All the constructional forms were shown boldly on the outside without any adornment; the west front of the narthex next to the atrium was alone covered with slabs of Proconnesian marble, some of which are still preserved, but the upper wall surfaces were perfectly plain.

In the interior the whole of the walls are plated with rare variegated marbles, and the vaults are covered with glass mosaic. Two chief masses of colour in the nave are separated horizontally by a cornice, and another cornice forms the springing for the vaulting. There are also cornices at the foot of the dome, and around the walls of the aisles. All these are of carved white marble in simple profiles. The lower range of arch spandrils between the piers of the nave is formed of slabs of white marble completely covered with carving: the upper spandrils above the gynaeceum arches have sectile work of coloured marbles. The carving is sharply cut, but conforms very closely to the general surfaces; according to the old descriptions it was gilt, and remains of colour still extant show some of the leaf-ornament coloured with a dark red.[260]

Columns.—Amongst the columns are beautiful examples of the dark green Thessalian marble, now called verde antico. Of this are formed all the round columns in the nave and ground-floor aisles, with the exception of the eight in the four exedras, which are of dark Theban porphyry. It could not have been always possible to find a sufficient number of columns of the same height and diameter, and the transport of them must have been frequently accompanied by injuries of one kind or another. There are differences between similarly situated columns, and in many cases mended fractures appear on the surface of the marble. In no cases are antique capitals placed on these columns. All the capitals and bases are of Proconnesian marble, and were wrought by Byzantine chisels.

The greater part of the capitals are similar in design, though their size varies in proportion to the height of the columns which support them. Salzenberg, in Figs, 1 and 3 of his Plate xv., shows one of the capitals of the great order. The leaf-work on them—partly acanthus and partly palm—is very deeply undercut, and lies almost clear of the ground underneath. In the middle of front and back are monograms.

Under the capitals are bronze rings eleven and half inches high; each is composed of three members, with a wrought lock on the side towards the nave, on which is repeated the monogram of each capital. At the foot of the columns above the bases are similar rings nine inches high. These rings occur on all the old columns, with the exception of the two dual columns of the west gallery. They seem to be let into the shaft, and, according to the description of the Silentiary, they were gilded. In addition to these rings, there are on other columns—as, for instance, the porphyry columns of the exedras—simple rings, rectangular in section, in positions where cracks and injuries appear; there being three or four such rings on a column at different heights. It is possible that some of these are of Turkish origin.

The bases as a rule have much the same form as the Attic base; the porphyry columns of the exedras have pedestals[261] below them, because the shafts were not long enough.

Each of the great verde antique shafts has a height of twenty-five and a half feet, and the bronze base-ring has an inside diameter of three feet seven inches. The capital is three feet ten inches high, and the upper part five feet eight inches wide, the whole height, including base and capital, being thirty-three and a half feet.

The porphyry columns of the western exedras have a total height of thirty-one feet; the shafts are twenty-two feet and three-quarters long, and the diameter at the bottom is three feet one inch. The capital is four feet high, and the abacus above measures towards the nave four feet nine inches, and towards the aisles four feet eleven inches. In the direction of the thickness of the arch the side of the abacus measures five feet, the variation being due to the circular plan of exedras.

The columns of the upper storey, which separate the gynaeceum and the nave, also of verde antique, stand nearer to one another and are smaller than those below. The total height of those in the middle division is twenty-two feet five inches; those in the exedras are twenty-one feet, with a diameter at the bottom of two and a quarter feet. The capitals are three and a half feet high, and the bases, including a six-inch bronze ring, two feet one inch.[262]

The parapet is three feet ten inches high, and of white marble.[263] It stands between the columns, and like them is set on a stylobate one foot six inches high, above the lower cornice. It should be noticed how the wide vaulting of the aisles is contrived, so as not to interfere with the view through the arched openings of the lower range of columns.

The columns in the interior of the ground-floor aisles are about twenty-four feet seven inches high. These capitals are similar to those already described. Those in the interior of the gynaeceum, with shafts of Proconnesian marble, have capitals of quite another form.[264] They are very similar to others in the church of SS. Sergius and Bacchus; the twin columns in the gynaeceum at the west end of the nave have similar capitals; the columns being verde antique. In these capitals, however, the volutes are not arranged diagonally, but show “cushions” at the side.

The capitals in the atrium resembled those of the twin columns; though the cushion was shorter and the top had less projection, and it was crowned with a flat egg and tongue moulding. The capitals and shafts were of white marble. The beautiful square capitals of the eight square white marble pillars in the aisles are shown in Salzenberg’s Plate xvi.

The arches of the great order have an elaborate leaf-ornament round them, continuing above the capitals in a horizontal line, resembling in fact an architrave. [In the centre above each capital is a cross, and at the crown of the arch is a four or six-armed cross.] The spandrils are filled with acanthus-ornament, and in the centre of each is a disc of coloured marble-surrounded by a carved circle in the white marble. The ornament of the intrados of the arches consists of five divisions in the width: these are covered with a continuous pattern, seven slabs casing the intrados of the arch. [The five bands are only carved alternately, the centre and lateral ones being plain.] See our [Fig. 50].

The respond on the main pier at each end of this arcade is a kind of pilaster strip,[265] surmounted by a capital in low relief, and surrounded by a notched border.

The two cornices running round the nave, which serve as galleries for the lamplighters, have an extremely simple profile. The slanting under-surface, divided horizontally by a row of beads, has acanthus-leaves in the upper part forming a cymatium, and in the lower modillions carved with ivy and acanthus, and between them, panels with different leaf-ornaments. Beneath the aisle cornice is a frieze of marble mosaic. The base mouldings or skirtings are worked out of thin slabs.[266]

Salzenberg’s Plate xx. contains a collection of architectural details, which seem to belong to different periods; Figs. 1, 2, 3 represent one of the white marble capitals which adorn the two porphyry columns of the south-east porch. The arch above them is Turkish, and hence it may be questioned if this was their original position: they seem more intended for an ornamental structure than to support a load, and they may perhaps have belonged to a ciborium above the holy table. The two marble capitals (Figs. 4 and 5), only three inches thick, were found in the chamber in the north-east buttress mass, above the gynaeceum roof, together with broken pieces from a window. They may originally have belonged to the upper part of the building, such as the window wall under the north arch of the dome.[267] The workmanship is very different from that in the rest of the church, and is more closely allied with ancient treatment. Perhaps they are fragments from the earlier church which found a fresh application in Justinian’s building. The parapet pillars between the twin columns of the western gynaeceum, with tall pedestals, are each formed in one piece of verde antique. Their capitals resemble those of the windows,[268] with the exception that the former are rounded underneath instead of being square.

The wood ties which span different arches are adorned on the sides and beneath with carvings.[269]

Windows and Doors.—The lighting of the church is most brilliant; wherever space or construction permitted, windows of considerable size were opened, so that light floods the whole church. At the foot of the dome the light streams in through forty windows, and each of the seven apses has five openings. The eastern sun sends its first rays through the six windows in the apse, and the setting sun shines through the great west lunette. There are twenty-four windows in the two great tympana, besides large windows in the aisles.

The windows in the conchs of the exedras are now closed up, the grouped windows in the great tympana on the north and south are diminished to insignificant openings, and the large arched openings at the sides or the end divisions of the aisles seem even in Byzantine times to have been reduced in size; at least the remains of piers, shown in Salzenberg’s Plate xiii., indicate that there was originally an opening with pilasters, similar to those at the eastern end of the side aisles.[270]

It is said that Justinian gave instructions that combustible materials should be avoided. If so, these instructions were followed even to the windows and doors, for the lattice-work of the former is of marble, and the panels of the latter are of bronze, or rather they are covered with bronze.

Salzenberg[271] gives the inside elevation and section of a window on the south side of the gynaeceum, with details on a larger scale. The opening in the wall is brick-arched, and the framework consists of upright posts, with a thin horizontal architrave dividing the window into two parts. Between these posts were fitted the breast-wall and lattice-work. The posts are narrow towards the outside, and the ends of the architrave rest on thin pieces against the jambs.

The ‘breast-wall’ at the bottom of the opening and the ‘lattice-work’ are formed of marble, three inches thick. The openings pierced in the slabs are about seven or eight inches high, filled with panes of glass. Between the panes the marble has a width of three and a half inches, slightly splayed on the inside. A second row of slabs fills the lower part of the windows pierced with openings, surrounded by wider margins.[272]

The great semicircular west window is divided vertically by two columns with plain capitals and bases; the horizontal division from column to column is similar to the crowning member of the breast-wall of the other windows. The lower part is filled with marble slabs, which conceal the roof of the western gynaeceum. Each panel is ornamented with a cross upon a circle, and within the latter is a monogram.

The small windows are simply filled with marble lattice for the glass. Inside the apse windows of the east end are other windows having coloured glazing; but these are evidently Turkish.

Marble door jambs were placed in the openings left in the walls, just as the posts were inserted in the windows; the middle, or Royal Door, from the narthex to the nave, is of bronze. All the frames were moulded, and above are fixed door-hooks, like bent forefingers; these held rings and leather fastenings, from which were suspended the customary door-hangings.

The lintel of the bronze door-frame bears a relief. This represents an arch, supported by columns above a throne with the book of the Gospel and the descent of the Holy Ghost in the form of a dove. On it are the words of S. John, ‘The Lord said, I am the door of the sheep; through me if any man enter, he shall enter and shall go out, and shall find pasture.’ The simple bronze door-plating now remaining does not seem to be original. [See p. [265].]

Salzenberg,[273] as an example of the marble frames, gives the east door of north aisle. Like all Byzantine door-frames, the head does not cut across the jamb, but mitres. This perhaps made it easier for fixing within the openings left in the walls. Salzenberg[274] also represents the arched opening, which stands between the Baptistery and the small court on the south side of the church.[275] There are two tiers of columns, with a thin architrave band between them. The door stands between the lower columns; to avoid concealing them the frame is made as small as possible, as the plan shows. A similar arrangement is found in the earlier church of S. John Studius.[276]

The bronze door-plating on the exterior of the south porch entrance is extremely interesting.[277] A wooden foundation four or five inches thick is covered with ornamental bronze casings. The borders to the panels are beautifully modelled, and must be ancient. The other outer margins, with knobs and rosettes, and the four panels, which are decorated with monograms, belong to the Byzantine school. In the more ancient parts the metal is one-eighth to one-fourth inch in thickness, in the latter it is three-eighths to half an inch. Antique doors must have been enlarged and fitted with new panel plates.

Marble Plating.—Broad horizontal bands run round the nave at different heights, and the spaces between them are filled with single panels and vertical sheathing. All the bands and panels have notched fillets, 1½″ wide, of white marble as borders. The more important panels have sculptured white marble frames, eleven inches wide with a “pater noster” and notched-fillet borders on either side.

The spandrils of the upper arches and the bands beneath the topmost cornices are incrusted with designs of leaves, flowers, fruits, and birds formed of different kinds of marble.

The marble casing to the walls of the nave is arranged as follows.[278] Above the skirting is a [3′.10″] band of verde antique, then the notched fillet, then a [1′.5½″] yellow band [oriental alabaster]; above this is a vertical sheeting [7′.10″] formed of Pavonazzetto marble, alternating with a yellowish brown marble; then another horizontal band of yellow.

Above this stretches a series of panels round the whole nave—a panel of rosso, with two vertical slabs of a dark marble like porto venere on either side, each surrounded by the sculptured frames. The space from the top of this series to the lowest cornice is adorned with two bands of yellow [alabaster], and between them is sheathing similar to that below.

The upper division of the nave starts above the cornice with horizontal bands of white and verde antique; above which are vertical panels of porphyry, set in a frame of yellow [alabaster], with slabs of the russet marble on either side. [Then follows another horizontal band of oriental alabaster, and above it a range of vertical slabs of verde antique alternating with Synnadan.]

Beyond this again, and immediately below the upper cornice, is the band made up of different marbles[279] [opus sectile]. A dark brown marble forms the groundwork, the tendril ornament is white, and the rest is of red, like rosso antico, and of green serpentine. Similar work incrusts the spandrils of the gynaeceum arcade. The centre of each is a disc of green marble, and the whole spandril is edged by a three-inch strip of pale red. Above the centre of each arch in this spandril decoration are discs containing crosses, from the arms of which hang seals.[280] The soffites of the arches are covered with glass mosaic. The aisles are lined with marbles similarly arranged to those in the nave.

The walls of the bema are covered with panels of inlaid marble.[281] These panels in pairs are separated by a plain slab of porphyry. By the side of the arched opening into the gynaeceum is a panel of porphyry with a pattern in slight relief, and surrounded with yellow alabaster. The arched opening into the gynaeceum is closed with a parapet of white marble, with a carved framework above, formerly fitted, as holes show, with a metal lattice.

The lower division of the bema walls is decorated by two rows of panels, divided by a horizontal band of verde antique. Salzenberg’s Plate xxii., Fig. 6, shows the frieze directly below the bema cornice, and the top of a porphyry pilaster-strip with a capital of white marble; a similar pilaster fills the narrow space on each side of the apse.

The walls of the apse are shown on Salzenberg’s Plate xxi. The frieze beneath the cornice is given in Plate xxii., Fig. 8. The porphyry ground has an inlaid pattern which slightly projects: the serpentine in the frieze, Fig. 6, also projects from its rosso ground. The lower portion of the apse, formerly occupied by the seats of the priests, is now plated with a white gray marble. This is probably Turkish. The height of this probably gives the height of the iconostasis, as there is no sign of any change in the decoration above.

The marble is fixed to the wall with a dark brown resin. In the opus sectile, pieces of coloured marble about a quarter of an inch thick were cut to the forms of the design, and then laid with their polished faces downward at the bottom of a mould; on this was poured a three-quarter inch backing of resin mixed with bits of stone and brick. When set, the slabs so formed were attached to the wall with cement. The large marble slabs are one to two inches thick, and, besides the cement, are fastened to the walls by iron [? bronze] clamps. The pavements of ground floor and gynaeceum are of white marble with dark gray stripes. [Proconnesian.] In the south-east angle of the square area under the dome is a square of marble mosaic, of which details are given in Salzenberg’s Plate xxii., Figs. 9-15. It is formed of a circular centrepiece of a gray brown granite, ten feet two inches in diameter, round which are arranged coloured marble discs of various sizes, set in a mosaic of marbles, with a little glass mosaic in the angles.

In the centre of the west end of the gynaeceum is a square [of about twenty-four feet] in the pavement laid with slabs of “gray cipollino” [Proconnesian], having a border of verde antique, with a patterned edging[282] of giallo and rosso on one side, and giallo and serpentine on the other. [Between this and the parapet is a circular slab of verde antique four feet seven inches in diameter.]