By maintaining the dignity of the empire, without attempting to enlarge its limits, the early emperors caused the Roman name to be revered among the most remote nations of the earth. The terror of their arms added weight and dignity to their moderation. They preserved peace by a constant preparation for war. The soldiers, though drawn from the meanest, and very frequently from the most profligate, of mankind, and no longer, as in the days of the ancient republic, recruited from Rome herself, were preserved in their allegiance to the emperor, and their invincibility before the enemy, by the influences of superstition, inflexible discipline, and the hopes of reward. The peace establishment of the Roman army numbered some 375,000 men, divided into thirty legions, who were confined, not within the walls of fortified cities, which the Romans considered as the refuge of pusillanimity, but upon the confines of the empire; while 20,000 chosen soldiers, distinguished by the titles of City Cohorts and Prætorian Guards, watched over the safety of the monarch and the capitol. "Wheresoever the Roman conquers he inhabits," was a very just observation of Seneca. Colonies, composed for the most part of veteran soldiers, were settled throughout the empire. Rich and prosperous cities, adorned with magnificent temples and baths and other public buildings, demonstrated at once the magnificence and majesty of the Roman system. In Britain, York was the seat of government. London was already enriched by commerce, and Bath was celebrated for the salutary effects of its medicinal waters. All the great cities were connected with each other, and with the capital, by the public highway, which, issuing from the Forum of Rome, traversed Italy, pervaded the provinces, and was terminated only by the frontiers of the empire. This great chain of communications ran in a direct line from city to city, and in its construction the Roman engineers snowed little respect for the obstacles, either of nature or of private property. Mountains were perforated and bold arches thrown over the broadest and most rapid streams. The middle part of the road, raised into a terrace which commanded the adjacent country, consisted of several strata of sand, gravel, and cement, and was paved with granite or large stones. Distances were accurately computed by milestones, and the establishment of post-houses, at a distance of five or six miles, enabled a citizen to travel with ease a hundred miles a day along the Roman roads.