Page:History of Indian and Eastern Architecture Vol 1.djvu/361

 CHAP. II. DOMES at what period it is not now known. The earliest example, the Pantheon, is also the finest and largest ; but we have lost entirely the innumerable steps by which the architects must have slowly progressed to so daring an experiment. There is, however, a vast difference between these two classes of domes, which it is necessary to bear in mind in order to understand what follows. The Roman arch and Roman dome are always constructed (Woodcut No. 170) on the principle of voussoirs, or truncated wedges, radiating from a centre. This enabled the Romans to cover much larger spaces with their domes than perhaps was possible on the horizontal principle ; but it involved the incon- venience of great lateral thrusts, continually tending to split the dome and tear the building in pieces, and requiring immense and massive abutments to counteract their destructive energy. 170. Radiating Arch. 171. Horizontal Arch. The Indian or horizontal dome never can be made circular in section, except when used on the smallest scale, but almost always takes a form more or less pointed (Woodcut No. 171). From the time of the building of the Treasury of Mycenae l to the birth of Christ, we have a tolerably complete series of arches and vaults constructed on this principle, but few domes properly so called. After the Christian Era the first example is found in a singular tomb at Mylassa, 2 near Halicarnassus in Caria, 3 where the dome exhibits all the peculiarities of construction found in the Jaina temples of India. After this we almost lose the thread of its history till the form reappears in porches like those of the I ith century on Mount Abu, where it is a perfectly established architectural feature, that must have been practised long before it could be used as we find it in that building. Whether we shall ever be able to recover the lost links in this chain is more than doubtful, but it would be deeply interesting to the history of art if it could be done. In the meantime, there is no difficulty in explaining the constructive steps by which the object is now attained in India. These may also throw some 1 ' History of Ancient and Mediaeval Architecture,' vol. i. p. 243. 3 Fully illustrated in vol. ii. of the
 * Ibid. p. 371 ; and ante, p. 209.
 * i~..i t : Society's ' Antiquities of

Dilettanti Ionia.'