developed in a succession of bells and inverted volutes, above which two bulls’ heads are arranged, even with the intercolumniations; this is the bicephalic capital, characteristic of the Achæmenid architecture, which has never been employed except in Persia. Other columns differ, but only in the base, from that which we have just described; the double torus supporting the shaft is sometimes placed, not on a square pedestal, but on a cylindrical drum, decorated with twenty-four vertical lines and growing gradually broader in the lower part, so as to present the form of a much elongated ogee or of a bell. At Susa, instead of lines, the ornament of the base is sometimes formed of elegant inverted foliage (fig. 126). The comparative study of the Achæmenid column, together with the monuments of Egypt and Greece, has led M. Dieulafoy to conclude that the outlines of the Persepolitan column are Egyptian, but that its structure is composed of Græco-Ionian elements. These volutes, strings of ovals, and tori at the base, had already become classical in the Hellenic world long before Cyrus, since they are found everywhere, at Mycenæ, Segesta and Selinus, in Attica and in Ionia: here again we are forced to recognise that the architect, even when he copies motives derived from Egypt or Assyria, is imbued with the principles of Hellenic art. [Illustration: Fig. 126.--Base of a column (after Dieulafoy).] Besides columns, the Persepolitan and Susian palaces had pilasters placed at the extremities of the porticoes, as continuations of the façades. In the façades of the palace of Darius at Persepolis two square pilasters of porphyry are seen, so perfectly preserved that in the upper part they still have holes, cut to receive the ends of the entablature. They would suffice to prove, if any proof were wanting, that in these structures, the columns, which are placed at long intervals and are tall and slender, did not support stone but wooden architraves. These were enormous beams which formed a line even with the tops of the columns, and, running from capital to capital, and placed in grooves contrived with this object, contributed to give homogeneity and solidity to the structure. Upon these great beams the rafters of the roof were arranged, and then a flat ceiling supporting neither a terrace nor a second story. [Illustration: Fig. 127.--Façade of the _Apadâna_ of Artaxerxes (restoration by M. Dieulafoy).]