It must be considered that these columnar halls were the equivalents of the modern throne-rooms, that here all public business was dispatched, and that here the king might sit and enjoy the beauties of the landscape.

With the rich plains of Susa and Persepolis before him, he could well, after his winter's residence at Babylon, dispense with massive walls, which would only check the warm fragrant breeze from those verdant prairies adorned with the choicest flowers.

A massive roof, covering the whole expanse of columns, would be too cold and dismal, whereas curtains around the central group would serve to admit both light and warmth.
Nothing can be conceived better adapted to the climate or the season.
If the central cluster of pillars was thus adapted to the purposes of a throne-room, equally well may the isolated colonnades have served as ante-chambers or posts for guards.

Protected, perhaps, with curtains or awnings of their own, of a coarser material than those of the main chamber, or at any rate casting, when the sun was high, a broad and deep shadow, they would give a welcome shelter to those who had to watch over the safety of the monarch, or who were expecting but had not yet received their summons to the royal presence.

Except in the very hottest weather, the Oriental does not love to pass his day within doors.