ARCHITECTURE. 97 
Architectonically the new Rome was only a phantom of the old. The 
magnificence of the latter was the fruit of many years of the prime of 
the empire and of art. In Constantine’s time the latter had declined. The 
colossus of the empire yet stood, but the springs of vitality were dried up. 
The emperor consequently, to build anew, was obliged to destroy the old. 
The tolerance of the Christian religion was proclaimed, and the old system 
fell, and with it fell all of artistic greatness and glory which the people had 
hitherto achieved, to serve as material for the new order. Only the techni- 
cality remained, and this was poor and awkward. Originally, the new 
city was to have been placed between Troas and Ilium, and the ground was 
even surveyed, and the marking out of the walls commenced, when 
the emperor altered his plan and chose the much more eligible site of 
Byzantium, where he had the further advantage that Byzantium was already 
a city, needing only improvements. Thus it could after a few years com- 
pete with Rome. 
Although the building of many Christian churches is ascribed to Constan- 
tine, yet the real number must be very small; for on the one hand, Con- 
stantine did not adopt the Christian religion until he was quite old, and 
on the other hand, all the churches contained columns from the heathen 
temples, and the yet vigorous power of the priests would not then have 
allowed free play to such vandalism, and the destruction of the buildings. 
But that Constantine’s immediate successors, and even members of his own 
family, executed such works, appears from the church of St. Agnes, which 
Constantine’s daughter, Constantia, built. It is a three-aisled basilica (pl. 
27, fig. 14, view; pl. 46, jig. 16, ground plan) of beautiful proportions but 
built of fragments, having columns of the Composite and Corinthian orders, 
and of various kinds of marble. Instead of straight architraves, arches are 
everywhere employed. At this time also was built the mausoleum of Helena, 
the sister of Constantine, on the Nomentanian Way. It was a circular 
edifice in the form of the Pantheon, with seven niches in the interior, and 
a vestibule of four columns. In this mausoleum was the beautiful porphyry 
sarcophagus, with bas-reliefs representing fighting horsemen and captive 
barbarians, which now stands in the museum Pio Clementino. Some author- 
ities ascribe this sarcophagus not to Helena the sister, but to Helena the 
mother of Constantine. Ammianus Marcellinus, however, tells us that a 
sarcophagus adorned with wreaths of plants, figures of children representing 
genii, a peacock, and a lamb, was found in a circular edifice like the former, 
which contained the grave of Constantine’s mother. Pius VI. had the 
sarcophagus brought to the Museum of the Vatican. 
7. Tue Orpers. 
Before we proceed to the architectural history of the middle ages, 
it will be necessary to say a few words upon the five orders of columns. 
As we remarked in our sketch of the architecture under the Roman emperors, 
all rules had fallen into oblivion with the decline of art towards the 
close of that period. The buildings of the period betray an uncertainty 
ICONOGRAPHIC ENCYCLOPZDIA.—VOL. Iv. 7 97 
