The favourite of Justinian was sacrificed to conjugal tenderness or domestic tranquillity; the conversion of a prefect into a priest extinguished his ambitious hopes, but the friendship of the emperor alleviated his disgrace, and he retained, in the mild exile of Cyzicus, an ample portion of his riches. Such imperfect revenge could not satisfy the unrelenting hatred of Theodora; the murder of his old enemy, the bishop of Cyzicus, afforded a decent pretence; and Joannes of Cappadocia, whose actions had deserved a thousand deaths, was at last condemned for a crime of which he was innocent. A great minister, who had been invested with the honours of consul and patrician, was ignominiously scourged like the vilest of malefactors; a tattered cloak was the sole remnant of his fortunes; he was transported in a bark to the place of his banishment at Antinopolis in Upper Egypt, and the prefect of the East begged his bread through the cities which had trembled at his name. During an exile of seven years, his life was protected and threatened by the ingenious cruelty of Theodora; and when her death permitted the emperor to recall a servant whom he had abandoned with regret, the ambition of Joannes of Cappadocia was reduced to the humble duties of the sacerdotal profession. His successors convinced the subjects of Justinian that the arts of oppression might still be improved by experience and industry; the frauds of a Syrian banker were introduced into the administration of the finances; and the example of the prefect was diligently copied by the quæstor, the public and private treasurer, the governors of provinces, and the principal magistrates of the Eastern Empire. The edifices of Justinian were cemented with the blood and treasure of his people; but those stately structures appeared to announce the prosperity of the empire, and actually displayed the skill of their architects. Both the theory and practice of the arts, which depend on mathematical science and mechanical power, were cultivated under the patronage of the emperors; the fame of Archimedes was rivalled by Proclus and Anthemius; and if their miracles had been related by intelligent spectators, they might now enlarge the speculations instead of exciting the distrust of philosophers. A tradition has prevailed that the Roman fleet was reduced to ashes in the port of Syracuse by the burning-glasses of Archimedes; and it is asserted that a similar expedient was employed by Proclus to destroy the Gothic vessels in the harbour of Constantinople, and to protect his benefactor Anastasius against the bold enterprise of Vitalian. A machine was fixed on the walls of the city, consisting of an hexagon mirror of polished brass, with many smaller and movable polygons to receive and reflect the rays of the meridian sun; and a consuming flame was darted to the distance, perhaps, of two hundred feet.