+ARCHITECTURAL DETAILS.+ The Persians, like the Egyptians, used the column as an internal feature in hypostyle halls of great size, and externally to form porches, and perhaps, also, open kiosks without walls. The great +Hall of Xerxes+ at Persepolis covers 100,000 square feet--more than double the area of the Hypostyle Hall at Karnak. But the Persian column was derived from wooden prototypes and used with wooden architraves, permitting a wider spacing than is possible with stone. In the present instance thirty-six columns sufficed for an area which in the Karnak hall contained one hundred and thirty-four. The shafts being slender and finely fluted instead of painted or carved, the effect produced was totally different from that sought by the Egyptians. The most striking peculiarity of the column was the capital, which was forked (Fig. 21). In one of the two principal types the fork, formed by the coupled fore-parts of bulls or symbolic monsters, rested directly on the top of the shaft. In the other, two singular members were interposed between the fork and the shaft; the lower, a sort of double bell or bell-and-palm capital, and above it, just beneath the fork, a curious combination of vertical scrolls or volutes, resembling certain ornaments seen in Assyrian furniture. The transverse architrave rested in the fork; the longitudinal architrave was supported on the heads of the monsters. A rich moulded base, rather high and in some cases adorned with carved leaves or flutings, supported the columns, which in the Hall of Xerxes were over 66 feet high and 6 feet in diameter. The architraves have perished, but the rock-cut tomb of Darius at Naksh-i-Roustam reproduces in its façade a palace-front, showing a banded architrave with dentils--an obvious imitation of the ends of wooden rafters on a lintel built up of several beams. [Illustration: FIG. 21.--COLUMN FROM PERSEPOLIS.] These features of the architrave, as well as the fine flutings and moulded bases of the columns, are found in Ionic architecture, and in part, at least, in Lycian tombs. As all these examples date from nearly the same period, the origin of these forms and their mutual relations have not been fully determined. The Persian capitals, however, are unique, and so far as known, without direct prototypes or derivatives. Their constituent elements may have been borrowed from various sources. One can hardly help seeing the Egyptian palm-capital in the lower member of the compound type (Fig. 21).