Part 2 (2/2)

The weight of the drum and dome rests on the pendentives and dome-arches. Their thrust is neutralized by the use of ties and by the barrel vaults of the cross arms, and these in their turn depend on the thickness of the walls. The lower buildings attached to the church in the form of side-chapels and the narthex also helped to stiffen and b.u.t.tress the cross walls. The system is by no means perfect in these late churches. It was apparently found impossible to construct drum domes of any size, except at the extreme risk of their falling in, and probably it is for this reason that many of the larger domes in late churches, like SS. Peter and Mark, S. Theodosia, the Chora, have fallen.

No system of chainage appears to have been used for domes in Constantinople.

Flying b.u.t.tresses probably of the ninth century are used at the west end of S. Sophia. The double-flying b.u.t.tress to the apse of the Chora does not bond with the building and is certainly not original. It may be set down as part of the Byzantine restoration of the church in the fourteenth century. In any case, such external flying abutments are alien to the spirit of Byzantine architecture, and may be regarded as an importation from the West. Flying b.u.t.tresses, it may here be noted, are not uncommon in the great mosques of the city. They are found in Sultan Bayazid, Rustem Pasha, Sultan Selim, the Suleimanieh, and the Shahzade.

But they are generally trifling in size, and are rather ornaments than serious attempts to b.u.t.tress the dome.

_Walls._--The walls of the earlier churches are built of large thin bricks laid with mortar joints at least as thick as the bricks, and often of greater thickness. Stone is used only in special cases, as in the main piers of S. Sophia, but monolithic marble columns are an important part of the structure. In the later churches stone is used in courses with the bricks to give a banded effect, and herring-bone, diamond, and radiating patterns are frequently introduced. The palace of the Porphyrogenitus, the parecclesion of the Pammakaristos, and Bogdan Serai, exhibit this style of work. As ill.u.s.trations of the method adopted in the construction of walls the following measurements may be given, the sizes being in centimetres:

+---------------------------------------+----------+--------------+ | | Brick. | Joint. | +---------------------------------------+----------+--------------+ | Parecclesion of the Pammakaristos | .08 | .04 | | 4 courses brick, 5 joints | .46 | --- | | S. John in Trullo | .03 | .07 to .09 | | Refectory of the Monastery of Manuel | .04 | .04 to .06 | | 4 course stone, 3 joints | .78 | --- | | 4 courses brick, 5 joints | .30 | --- | | | { .0375 | .052 | | Bogdan Serai | { .035 | .035 | | | { .04 | .04 | | 4 courses stone, 8 joints | --- | .55 to .60 | | 4 courses brick, 5 joints | --- | .43 to .47 | | Sanjakdar, brick | .045 | --- | +---------------------------------------+----------+--------------+

_Building Procedure._--The first step in the erection of a building was to obtain the necessary marble columns with their capitals and bases.

These seem to have been largely supplied ready made, and Constantinople was a great centre for the manufacture and export of stock architectural features. Then the main walls were built in brick, the columns were inserted as required, the vaults were thrown, and the whole building was left to settle down. Owing to the enormous amount of mortar used this settling must have been very considerable, and explains why hardly a plumb wall exists in Constantinople, and why so many vaults show a p.r.o.nounced sinking in at the crown or have fallen in and have been rebuilt. After the walls had set the marble facings, mosaic, and colour were applied and could be easily adapted to the irregular lines of the walls.

Byzantine architecture made little use of mouldings. The great extension of flat and s.p.a.cious decoration rendered unnecessary, or even objectionable, any strong line composition. External cornices are in coursed brick, the alternate courses being laid diagonally so as to form the characteristic dentil. The richest form is that found in the Pammakaristos, S. Theodosia, and S. Thekla, where the small dentil cornice is supported on long tapering corbels, a design suggested by military machicolations.

[Ill.u.s.tration: PLATE IV.

(1) S. SAVIOUR IN THE CHORA. BRACKET IN THE INNER NARTHEX.

(2) S. THEODORE. SCULPTURED MARBLE SLAB BUILT INTO THE MINARET OF THE MOSQUE.

(3) S. MARY DIACONISSA. HEADS OF WINDOWS IN SOUTH ARM.

(4) S. MARY DIACONISSA. SCULPTURED SLAB ON THE WEST WALL.

_To face page 28._]

The stone ogee, cavetto, or cavetto and bead cornice is common, but seems in every case to be Turkish work and is very common in Turkish buildings. Internal cornices and string-courses are in marble, and are all of the same type, a splay and fillet. The splayed face is decorated with upright leaves or with a guilloche band, either carved (in the Pantepoptes) or painted (in the Chora), the carving as in cla.s.sic work, serving only to emphasise the colour. The splay is sometimes slightly hollowed, sometimes, as in the Chora, worked to an ogee.

_Doors._--Doors often have elaborately moulded architraves and cornice.

In S. John of the Studion (p. 61), the oldest example, the jamb-moulding has a large half-round on the face, with small ogees and fillets, all on a somewhat ma.s.sive scale. The doors of S. Sophia are very similar. The later mouldings are lighter but the half-round on the face remains a prominent feature. It is now undercut and reduced in size, and resembles the Gothic moulding known as the bowtell. This is combined with series of fillets, small ogees, and cavettos into jamb-moulds of considerable richness. The cornices are often simply splayed or are formed of a series of ogees, fillets, and cavettos. The jamb-mouldings are cut partly on a square and partly on a steep splayed line. In some, the portion forming the ingo seems to have been regarded as a separated piece though cut from the solid. If in the doors of the Pantokrator or the Pantepoptes the line of the inner jamb be continued through the rebate, it will correspond on the outside with the bowtell moulding, as though the inner and outer architrave had been cut from one square-edged block, placing the bowtell at the angle and adding the rebate. This formation is not followed in S. John of the Studion.

_Carving._--Carving is slight, and is confined to capitals, string-courses, and the slabs which filled in the lower parts of screens and windows. Fragments of such slabs are found everywhere. They are carved with geometrical interlacing and floral patterns, often encircling a cross or sacred monogram, or with simply a large cross.

Such slabs may be seen still in position in S. Sophia and in the narthex of S. Theodore. In the latter they are of verd antique, and are finely carved on both sides. In later times the embargo on figure sculpture was considerably relaxed. Little figures are introduced in the cornices of the eikon frames in the Diaconissa (p. 186), and both in the parecclesion and the outer narthex of the Chora are found many small busts of angels, saints, and warriors carved with great delicacy. The carving in the Chora is the finest work of the kind excepting that in S.

Sophia.

_Capitals._--The development of the capital from the Roman form, which was suitable only for the lintel, to the impost capital shaped to receive an arch has been well explained by Lethaby and Swainson.

According to these authors Byzantine capitals exhibit seven types.

I. The Impost capital.--It is found in SS. Sergius and Bacchus, the outer narthex of the Chora, the inner narthex of S. Andrew and elsewhere. A modification of this type is used in windows. It was employed throughout the style but especially in early times up to the sixth century, and again in the twelfth, thirteenth, and fourteenth centuries.

II. The Melon type.--This is seen on the columns of the lower order in SS. Sergius and Bacchus and on the columns of the narthex of S.

Theodore, where they have been taken from an older building. The melon capital was probably not in use after the sixth century.

III. The Bowl capital.--This type is used in the great order of S.

Sophia at Constantinople. It has been thought peculiar to this church, but the capitals from S. Stephen at Triglia in Bithynia resemble those of S. Sophia closely. Only the peculiar volutes of the S. Sophia capitals are absent.[34]

IV. The Byzantine or 'Pseudo-Ionic.'--This is found in the upper order of SS. Sergius and Bacchus, and in the narthex of S. Andrew. It is an early type, not used after the sixth century, and its occurrence in S.

Andrew favours the early date a.s.signed to that church.

V. The Bird and Basket.--Found in Constantinople, only in S. Sophia.

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