الشروحات المرفقة والمخططات واألشكال مصدرها كتاب

Transcription

1 الشروحات المرفقة والمخططات واألشكال مصدرها كتاب A history of Architecture By: Banister Fletcher s الطبعة الثامنة عشر. 1. Period of Byzantine Architecture: From (330 A.C.) To (1453 A.C.), and later. It is the Eastern department of Roman Empire. (fig.1&2) Byzantium renamed Constantinople after Constantine the Great, its Imperial founder, and also called (New Rome), was inaugurated of the Roman Empire in 330 A.D. c. (Fig.1 The Roman Empire) (Fig. 2 The Division of The Empire) Page 1 of 12

2 2. Influences Factors: A. Geographical Factors: The Position: - It stood at the junction of the Bosphorus and the Sea of Marmora, where Europe and Asia are divided by only a narrow strip of water. - This gave it a commanding and central position for the government of the eastern and most valuable part of the Roman Empire. - It was also at the intersection of two great highways of commerce, the water highway between the Black Sea and Mediterranean, and the trade route between Europe and Asia. - The natural harbor of the Golden Horn possesses advantages for commerce. - For its four miles in length, unaffected by tides, and of sufficient depth to render its quays accessible to ships of deep draught. Byzantine Art : - Pervaded all parts of the Eastern Roman Empire and was carried by traders to Greece, Serbia, Russia, Asia Minor, North Africa and further west, and it had considerable influence on the architecture of these districts. B. Geological Factors: Building Material: - Constantinople had no good building stone, and local material such as clay for bricks and rubble for concrete were employed. - Other materials more monumental in character had therefore to be imported (marble was brought from the quarries in the islands). - Byzantine architecture was further considerably influenced by the multitude of monolithic columns of such sizes as were obtainable from the different quarries. C. Climatic Factors: The Roman adapted their methods of building to suit the needs of the new eastern capital and to those conditions of life which had there already created traditional forms of art, thus these features formed the style of Byzantine architecture: - Flat roofs for summer resort were combined with oriental domes. - With small windows often high up in otherwise unbroken wall. - Sheltering arches surrounded the open courts. Page 2 of 12

3 D. Historical And Social Factors: Byzantium was founded as a Greek colony c. 660 B.C., and in 300 A.D. became the capital of Roman Empire. The empire was finally divided by the death of Emperor (Theodosius I (305 A.C.)), and Byzantium continued to be the capital of the Eastern Empire. In the Middle Ages was the bulwark of Christianity against the attacks of Slav barbarians on the west, and of Moslems on the east. The great building activity in the west division, from ( A.D.), influenced on Byzantine architecture. From ( A.D.) Sicily and Italy were recovered to Eastern Empire, and this new connection promoted a revival of building in Italy, here again Byzantine influence came into play. From before ( A.C.) 3. Architectural Character: The character of Byzantine architecture, which dates from the (5 c A. D. To the present days): Is determined by the novel development of the dome to cover polygonal and square. )المعمودية مبنى ديني( plans for churches, tombs and baptisteries The practice of using a domical system of roof construction is in strong contrast to the Early Christian timber trusses and the Romanesque system of stone vaults. The basilican type of plan belongs to Early Christian architecture. The domed, centralized type of plan to the byzantine. During the first centuries of the Byzantine Empire, we can find domical constructions in Italy and basilican plans in the Eastern Empire. The system of construction in hand-laid concrete, introduced by the Romans, progressively had become more like regular brickwork, and in this form was adopted by the Byzantines. The brickwork was first completed and allowed to settle before the interior surface sheathing of unyielding marble slabs was added, and this independence of the component parts is characteristic of Byzantine construction (fig.3 m). Brickwork, moreover, lent itself externally to decorative caprices in patterns and banding, and internally it was suitable for covering with marble, mosaic and fresco decoration. The Byzantines therefore took great pains in the manufacture of bricks, which were employed alike in military,)عسكرية( ecclesiastical )كنيسية( and domestic. architecture )محلية( Page 3 of 12

4 The ordinary bricks were like the Roman, about 38mm (1 ½ ins) in depth, and were laid on thick beds of mortar. Fig. 3 Page 4 of 12

5 The general use of brickwork necessitated ) )إستتتت(ل special care in making mortar, )البالط( tiles,)فخار( and sand with crushed pottery )كلس( lime which was composed of or bricks, and much of it remains as hard as that in the best building of Rome. The decorative character of external facades depended largely on the arrangement of the facing bricks, which were not always laid horizontally, but : - sometimes obliquely. - sometimes in the form of the meander fret. - sometimes in the chevron or herring-bone pattern. And in many other similar designs, giving great variety to the facades. To ornament the rough brick exteriors by the use of stone bands and decorative arches. The Dome, a traditional feature in the east, because the prevailing motif )نمط( of Byzantine Architecture, which was a fusion ) إنتتت متتتا )إنصتتتتتتتتنتتتار of the domical construction with the Classical columnar style. Domes of various types (fig. 3, A, B, C) were now placed over square compartments ) مستتتتتتتتتانتتت ر )مقصتتتتتتوراس by means of pendentives (fig. 3, fig.374, 484,391), where in Roman architecture domes were only used over circular or polygonal structures. These domes were usually constructed of brick or of some light porous stone, such as pumice, or even of pottery, as in (fig.6, D). Some domes and vaults were constructed without temporary support or centering by the simple use of large flat bricks, and this is a quite distinct system probably derived from Eastern methods, such as the church of S. John at the (11 th c. A.D.). Windows were formed in the lower portion of the dome which, in the later period, was hoisted upon a high drum إستتتت(وانة( ")طبلة a feature which was still further developed in western Renaissance architecture by the addition of an external peristyle such as: S. Sophia: 1. The haunches were strengthened by a ring of small buttresses to compensate for the weakening effect of the window openings (fig.373, 384). 2. The grouping of small domes or semi-domes round the large central dome was effective (fig.373, fig. 3 M). 3. And one of the characteristic features of Byzantine churches was that the forms of the vaults and domes were visible externally, undisguised by any timbered roof (fig.384 A, D). Page 5 of 12

6 Thus in the Byzantine style the exterior closely corresponds with the interior. Some Domes Characters : Some Domes churches, there are tall bulbous wooden framed domes above the true domes (fig.391 B). Fig. 6 Page 6 of 12

7 Some Domes do not show outwardly at all, as with the bema dome at Hosios looukas (fig. 397A), or the dome above the eso-narthex at Nea Moni (fig.396). The perfect expression of Byzantine style: The columns are not merely ornamental, but really support the galleries, and semicircular arches rest directly on columns with capitals suitable for supporting the springers of arches of which the voussoirs were rectangular blocks, not set in receding moulded planes as in mediaeval architecture (fig. 465A,B). The Byzantine capital was shaped to from a simple transition from the square abacus to the circular shaft. The numerous columns, such in S. Sophia, exhibit the remarkable and beautiful structural expedient of surrounding the shafts, both under the capital and above the base, by bronze annulets.(fig. 3 N, fig. 7 A,B) Monolithic shafts which, owning to the height required, had to be set up contrary to the stratification of the quarry, were therefore liable to split, and these bronze annulets not only overcame this danger, but also prevented the lead seating from being forced out by the superincumbent weight. The marble columns from old buildings were utilized, the importation of newly-quarried columns and rare marbles for decorative purposes continued, and the Theodosian code encouraged and regulated this industry, so that colored marble were employed to a greater extent than in preceding style. The interiors were beautified by pavements in opus sectile or opus Alexandrinum (fig. 466K), and in domes and apses by colored mosaic, which were of glass rendered opaque by oxide of tin, an invention which had also been employed in the Early Cheistian Architecture. Marbles and Mosaic were used broadly to make a complete lining for a rough carcase, and mouldings were replaced by decorative bands formed in the mosaic. This use of mosaics resulted in the rounding of angles and, with the absence of mouldings and cornices, the designs and pictures continued uninterrupted on a universal golden ground over apses, walls, arches and pendentives upwards to the dome. In late examples fresco painting was often used instead of mosaic. Page 7 of 12

8 The character of Byzantine architecture shows development in its three main periods: : including the reign of Justinian : including the Macedonian and Comnenian dynasties to recent times: the character was also affected by local influences. Fig. 7 Page 8 of 12

9 4. Example: (Churches) A. Mains Characters : o Byzantine churches are distinguished by the centralized type of plan. o Having a dome over the nave )المذبح( which: In early examples, is sometimes supported by semi-domes. In later examples the churches are much smaller and the domes is raised upon a high drum with, occasionally, additional smaller domes rising at a lower level. o There is usually a narthex الكنيسة(,)صحن or entrance porch دخول(,)بنو at the west end, and the east end is cut off from the nave by an iconostas or screen of pictures. B. Examples: 1. SS. Sergius and Bacchus, Constantinople:(fig. 8, fig. 9A,B) o Erected by Justinian. o Is nearly square on plan (33m*28m). o It has four colonnaded exedrae to the central octagon, and the arrangement of the interior is similar to that in (fig. 6 G) o The church had a dome on pendentives placed over an intervening square and the whole doubled in size. o The dome over the central space, 16m in diameter and 21.2m high. o The dome is visible externally, and has a speculiar, melon-like form with ridges and furrows from base to summit (fig.3 H, J, K). 2. S. Vitale, Ravenna: (fig.6) o An inner ثماني( octagon )شكل of (16,6m) is enclosed by an outer octagon of (35m). o The apsidal chancel is successfully designed to open direct form one side of the inner octagon, while the other seven arches enclose columns, in two tiers placed on a semicircle, and these are reminiscent of the exedrae of (fig.7). o The lower columns carry the gallery usual in eastern churches and the upper columns terminate in squinches adjacent to the arches referred to above. o It is upon the eight great arches and piers it is constructed f earthen pots fitted into each other, those in the upper part being laid horizontally, thus producing a lightness of structure which did not require the arches and buttresses found necessary in above churches. o This remarkable construction is protected by a timber roof, thus differing from Roman usage and approximating to the practice which prevailed among mediaeval architects (fig.6). Page 9 of 12

10 o The walls, being carried up to support the timer-roof, act as haunches and assist in directing the thrust of the dome downwards. o The interior is remarkable for the beauty of its carved capitals with dosseret blocks (fig. 10C), while the mosaic which line the walls of the sanctuary are unique in this form of Christian art. o The exterior in large thin bricks with thick mortar joints is characteristic of the simple external treatment as the churches in (fig. 8). Page 10 of 12

11 Page 11 of 12

12 3. S. Sophia, Constantinople: (fig. 373, fig. 374, fig.name. o Page 12 of 12