aced the sea to the south, and along this side were the imperial
apartments with the open loggia of fifty arches raised above the water
upon massive substructures. The plan is not quite square, but imitates a
Roman camp, with great square towers at the angles, a gate in the centre
of each of three sides flanked with octagonal towers, and with smaller
square towers between gates and angles. Towards the sea was a water gate
on a lower level. The material is marble from Trau and Brazza
limestone. The sea facade is about 550 ft. long, the north about 530
ft., the east and west some 620 ft. The external walls are double
throughout, of worked stone filled in with concrete, the thickness being
6 ft. 6 in., and the height from 60 to 80 ft. On the three land facades
are double-arched windows 20 ft. from the ground, 6 ft. 6 in. broad, and
a little over 11 ft. high. Only three of the angle towers remain, the
fourth having fallen in 1555. The principal gateway is towards Salona,
and is known as the Porta Aurea. Above the gate itself is an open arch
flanked by niches on each side; above them are brackets which sustained
the columns of a higher row of seven niches, the whole forming a
grandiose architectural composition, of which the illustration shows the
effect. The passage-way is 13 ft. high by 11 ft. 3 in. wide. The other
gates are known as the Porta Ferrea and Porta Argentea. The latter has
practically disappeared; the former is over 14 ft. high, and the same
width as the Porta Aurea, but without its architectural magnificence.
These gates gave entrance to streets which divided the palace into
quarters, that from the Porta Aurea leading to the great peristyle,
around and beyond which were the public buildings and the imperial
apartments, while the women's quarter was probably to the west of this
street, and the officials' rooms to the east, the street at right angles
separating them from the more important parts of the palace.

[Illustration: THE PORTA AUREA, SPALATO

_To face page 293_]

[Illustration: DOOR OF THE "ATRIO ROTONDO," PALACE OF DIOCLETIAN,
SPALATO

_To face page 294_]

The colonnade of the peristyle, which is 114 ft. by 50 ft., consists of
six free-standing columns of red granite on each side and four at the
end. Those at the sides support arches beneath an architrave continued
across the end and rising into an arched form over the central space
beneath the pediment. This portion is raised several steps above