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JULY, 1915]
THE DOME IN PERSIA
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the turning point C, in direction A. D. Now the thrust K of the upper part E is in the same direction more or less, and thus the projecting part adds to the difficulty instead of helping matters. This is shown when it comes to practical work by the interior construction of this dome, which has a series of tie-bars T, fixed at their extremities in the lower part of the sides of the dome and meeting in the centre, where they are carried by a pile of masonry M.40 They are an imperative necessity to neutralise the unscientific shape chosen for the construotion of the dome, and by their very existance refute Saladin's theory that "la forme bulbeuse présente alors l'avantage de conserver sensiblement, à l'aplomb de l'arc du mur du tambour, la projection du centre de gravité du segment le plus important de la cupole, donc de ramener la poussée à l'intérieur du mur." (p. 365).
It is now clear to us that the shapes of the domet of the Bibi Khanam and Gûr Amir could not have sprung from constructive necessities in brick or stone. When we find this to be the case with other features in architecture, we usually find that the feature in question is a copy of
Fig. 18. construction in wood, e. g., the mortised joints of the stone rail round the Sánchí Tope, 11 also the metopes and triglyphs of the Doric order, the Lycian tombs in the British Museum, eto. Can it be so in the case of the bulbous double domes? Is there, or was there, anywhere in the Moslem world known to Timur, a double dome with swelling outline? Yes! at one place, and at one place only, and that was at Damascus, where stood the great Umayyad Mosque built by the Khalif Walid in A. D. 705-13, the dome of which in Timûr's time was double and of wood.
The following details concerning this mosque are taken from Professor Phené Spiers' " Architecture East and West."43 In plan it was as shown in (Fig. 19 ) It consists of three aisles and a transept at the intersection of which there was a dome B, which was called the Kubbat-anNasr (the vulture dome); the dome was considered as the head, the aisle below as the breast, while the lofty transept roofs, high above the rest, were likened to
Fig. 10. outspread wings. The sides of the square around B measure 39 feet 6 inches. The angles of this square are vaulted over with squinch pendentives, and the drum resting upon the octagon thus formed is set back 2 feet so that the dome resting upon it has an internal diameter of 43 feet 6 inches. There is a range of windows in the present drum and a second range in the dome, which is built of stone and covered with lead.
This is as things were before the fire of 1893, and the above dome was built at some date subsequent to the burning of the mosque at the sacking of Damascus by Timûr in 1400.
Descriptions of the mosque at various dates previous to this are to be found in the diaries of the various Arab geographers who visited it between the 9th and 14th centuries.
A
40 Saladin, op. cit. p. 361.
Fergusson, Indian Architecture, Vol. I, p. 111.
2 pp. 213-44.
