F. 10.--Yet another inscription worth notice was unearthed in 1897, and tells how a water supply to Cilurnum was brought from a source in the neighbourhood through a subterraneous conduit by Asturian engineers under Ulpius Marcellus (A.D. 160). That this should have been done brings home to us the magnificent thoroughness with which Rome did her work. Cilurnum stood on a pure and perennial stream, the North Tyne, with a massively-fortified bridge, and thus could never be cut off from water; it was only some six acres in total area; yet in addition to the river it received a water supply which would now be thought sufficient for a fair-sized town.[304] Well may Dr. Hodgkin say that "not even the Coliseum of Vespasian or the Pantheon of Agrippa impresses the mind with a sense of the majestic strength of Rome so forcibly" as works like this, merely to secure the passage of a "little British stream, unknown to the majority even of Englishmen." SECTION G. Death of Severus--Caracalla and Geta--Roman citizenship--Extended to veterans--_Tabulae honestae, missionis_--Bestowed on all British provincials. G. 1.--This mighty work kept Severus in Britain for the rest of his life. He incessantly watched over its progress, and not till it was completed turned his steps once more (A.D. 211) towards Rome. But he was not to reach the Imperial city alive. Scarcely had he completed the first stage of the journey than, at York, omens of fatal import foretold his speedy death. A negro soldier presented him with a cypress crown, exclaiming, "_Totum vicisti, totum fuisti. Nunc Deus esto victor_."[305] When he would fain offer a sacrifice of thanksgiving, he found himself by mistake at the dark temple of Bellona; and her black victims were led in his train even to the very door of his palace, which he never left again. Dark rumours were circulated that Caracalla, who had already once attempted his father's life, and was already intriguing with his stepmother, was at the bottom of all this, and took good care that the auguries should be fulfilled. Anyhow, Severus never left York till his corpse was carried forth and sent off for burial at Rome. With his last breath he is said solemnly to have warned "my Antonines" that upon their own conduct depended the peace and well-being of the Empire which he had so ably won for them.[306] G. 2.--The warning was, as usual, in vain. Caracalla and Julia were now free to work their will, and, having speedily got rid of her son Geta, entered upon an incestuous marriage. The very Caledonians, whose conjugal system was of the loosest,[307] cried shame;[308] but the garrison of the Wall which kept them off was, as we have seen, officered by Julia's creatures, and all beyond it was definitely abandoned,[309] not to be recovered for two centuries.[310] The guilty pair returned to Rome, and a hundred and thirty years elapsed before another Augustus visited Britain.[311]