the art made rapid advances under the powerful patronage of the aristocracies in some cities, as at Sparta, and of the tyrants in others, as Cypselus at Corinth, Theagnes at Megara, Cleisthenes at Sicyon, the Peisistratids at Athens, and Polycrates at Samos. Architecture now assumed decidedly the character of a fine art, and became associated with the sister arts of sculpture and painting, which are essential to its development. Magnificent temples sprung up in all the principal Greek cities; and while the Doric order was brought almost, if not quite, to perfection, in Greece Proper, in the Doric colonies of Asia Minor, and in Central Italy and Sicily, the Ionic order appeared, already perfect at its first invention, in the great temple of Artemis at Ephesus. The ruins still existing at Paestum, Syracuse, Agrigentum, Selinus, Aegina, and other places, are imperishable monuments of this period. To it also belong the great works of the Roman kings. The commencement of the third and most brilliant period of the art was signalized by the rebuilding of Athens, the establishment of regular principles for the laying out of cities by Hippodamus of Miletus, and the great works of the age of Pericles, by the contemporaries of Phidias, at Athens, Eleusis, and Olympia. The first part of the fourth period saw the extension of the Greek architecture over the countries conquered by Alexander, and, in the West, the commencement of the new style, which arose from the imitation, with some alterations, of the Greek forms by Roman architects, to which the conquest of Greece gave, of course, a new impulse. By the time of Augustus, Rome was adorned with every kind of public and private edifice, surrounded by villas, and furnished with roads and aqueducts; and these various erections were adorned by the forms of Grecian art; but already Vitruvius begins to complain that the purity of that art is corrupted by the intermixture of heterogeneous forms. This process of deterioration went on rapidly during the fifth period, though combined at first with increasing magnificence in the scale and number of the buildings erected. The early part of this period is made illustrious by the numerous works of Augustus and his successors, especially the Flavii, Nerva, Trajan, Hadrian, and the Antonines, at Rome and in the provinces; but from the time of the Antonines the decline of the art was rapid and decided. In one department a new impulse was given to architecture by the rise of Christian churches, which were generally built on the model of the Roman Basilica. One of the most splendid specimens of Christian architecture is the church of S. Sophia at Constantinople, built in the reign of Justinian, A.D. 537, and restored, after its partial destruction by an earthquake, in 554. But, long before this time, the Greco-Roman style had become thoroughly corrupted, and that new style, which is called the Byzantine, had arisen out of the