At the western corner of the Arch of Severus are the scanty remains of a tall conical pyramid, about fifteen feet in diameter, which is identified as the Umbilicus Romæ, placed in the exact centre of old Rome. Not far from it stood the Milliarium Aureum, or Golden Milestone, on which were inscribed all the distances of roads without the walls. The Roman roads throughout the empire terminated at this point. With this central milestone was connected that admirable system of roads which the Romans constructed in our distant island; and it is a remarkable circumstance that the principal railway lines in England are identical with the general direction of the old Roman roads. The Antonine Way is now the Great Western Railway, and the Roman Watling Street, which ran diagonally across the country from Chester in the north-west to Dover in the south-east, is now replaced by the Dover, London, Birmingham, Grand Junction, Chester, and Crewe Railways. The reason of this union of ancient and modern lines of communication is obvious. The Romans formed their roads for the purpose of transporting their armies from place to place, and at certain distances along the roads a series of military stations were established. In course of time these stations became villages, towns, and cities such as Chester, Leicester, Lancaster, Manchester. Thus, strange as it may appear, the Milliarium Aureum of the Roman Forum has had much to do with the origin of our most ancient and important towns, and with the formation of the great lines of railway that now carry on the enormous traffic between them.
The exposed vaults immediately behind the Arch of Severus, bounding the Forum in this direction, are richly draped with the long, delicate fronds of the maidenhair fern. Shaded from the sun, it grows here in the crevices of the old walls in greater luxuriance and profusion than elsewhere in the city. There is something almost pathetic in this association of the frailest of Nature's productions with the ruins of the most enduring of man's works. Strength that is crumbling to dust and ashes, and tender beauty that ever clings to the skirts of time, as she steps over the sepulchres of power, have here in their combination a deep significance. The growth of the soft fern on the mouldering old stones seems like the sad, sweet smile of Nature over a decay with which she sympathises, but which she cannot share. The same feeling took possession of me when, wandering over the ruins of the Palaces of the Cæsars on a sunny February afternoon, I saw above the hoary masses of stone the rose-tinted bloom of almond-trees. Out of the gray relics of man's highest hour of pride, the leafless almond-rod blossomed as of old in the holy place of the Hebrew Tabernacle; and its miracle of colour and tenderness was like the crimson glow that lingers at sunset upon Alpine heights, telling of a glory that had long vanished from the spot.