Such was the proud capital,—­a city of palaces, a residence of nobles who were virtually kings, enriched with the accumulated treasures of ancient civilization.  Great were the capitals of Greece and Asia, but how pre-eminent was Rome, since all were subordinate to her!  How bewildering and bewitching to a traveller must have been the varied wonders of the city!  Go where he would, his eye rested on something which was both a study and a marvel.  Let him drive or walk about the suburbs,—­there were villas, tombs, aqueducts looking like our railroads on arches, sculptured monuments, and gardens of surpassing beauty and luxury.  Let him approach the walls,—­they were great fortifications extending twenty-one miles in circuit, according to the measurement of Ammon as adopted by Gibbon, and forty-five miles according to other authorities.  Let him enter any of the various gates that opened into the city from the roads which radiated to all parts of Italy and the world,—­they were of monumental brass covered with bas-reliefs, on which the victories of generals for a thousand years were commemorated.  Let him pass through any of the crowded thoroughfares,—­he saw houses towering scarcely ever less than seventy feet, as tall as those of Edinburgh in its oldest sections.  Most of the houses in which this vast population lived, according to Strabo, possessed pipes which gave a never-failing supply of water from the rivers that flowed into the city through the aqueducts and out again through the sewers into the Tiber.  Let the traveller walk up the Via Sacra,—­that short street, scarcely half a mile in length,—­and he passed the Flavian Amphitheatre, the Temple of Venus and Rome, the Arch of Titus, the Temples of Peace, of Vesta, and of Castor, the Forum Romanum, the Basilica Julia, the Arch of Severus, the Temple of Saturn, and stood before the majestic ascent to the Capitoline Jupiter, with its magnificent portico and ornamented pediment, surpassing the facade of any modern church.  On his left, as he emerged from beneath the sculptured Arch of Titus, was the Palatine Mount, nearly covered by the palace of the Caesars, the magnificent residences of the higher nobility, and various temples, of which that of Apollo was the most magnificent, built by Augustus, of solid white marble from Luna.  Here were the palaces of Vaccus, of Flaccus, of Cicero, of Catiline, of Scaurus, of Antoninus, of Clodius, of Agrippa, and of Hortensius.  Still on his left, in the valley between the Palatine and the Capitoline, though he could not see it, concealed from view by the great Temples of Vesta and of Castor, and the still greater edifice known as the Basilica Julia, was the quarter called the Velabrum, extending to the river, where the Pons Aemilius crossed it,—­a low quarter of narrow streets and tall houses where the rabble lived and died.  On his right, concealed from view by the Aedes Divi Julii and the Forum Romanum, was that magnificent series of edifices extending from