[Illustration: 031.jpg THE TWO IRANIAN ALTAKRAT NAKHSH-Î-RUSTEM]

Drawn by Boudier, from a heliogravure in Marcel Dieulafoy.

Two altars were usually set up together, and they are thus found here
and there among the ruins, as at Nakhsh-î-Kustem, the necropolis of
Persepolis, where a pair of such altars exist; these are cut, each out
of a single block, in a rocky mass which rises some thirteen feet above
the level of the surrounding plain. They are of cubic form and
squat appearance, looking like towers flanked at the four corners by
supporting columns which are connected by circular arches; above a
narrow moulding rises a crest of somewhat triangular projections; the
hearth is hollowed out on the summit of each altar.*

* According to Perrot and Chipiez, "it is not impossible
that these altars were older than the great buildings of
Persepolis, and that they were erected for the old Persian
town which Darius raised to the position of capital."

At Meshed-î-Murgâb, on the site of the ancient Pasargadas, the altars
have disappeared, but the basements on which they were erected are
still visible, as also the flight of eight steps by which they were
approached. Those altars on which burned, a perpetual fire were not
left exposed to the open air: they would have run too great a risk
of contracting impurities, such as dust borne by the wind, flights of
birds, dew, rain, or snow. They were enclosed in slight structures, well
protected by walls, and attaining in some cases considerable dimensions,
or in pavilion-shaped edifices of stone adorned with columns.

[Illustration: 032.jpg THE TWO IRANIAN ALTARS OF MURGAB]