The Chapel of St. Nazario and St. Celso, erected at Ravenna in the fifth century, contains the only tombs which remain in their places of the whole line of Cæsars, whether oriental or occidental. Thenceforth dates a new monumental art, equally separate from the old world. Out of the arch came the vault, and out of the vault the cupola, that majestic ornament to which every other feature is subordinate, and which is the very life and soul of Byzantine architecture. The inspiration of the Cross produced nobler forms of outline than Ictinus or Callicrates could bestow on their most sumptuous works, when its spreading arms reared aloft the mighty lantern of St. Sophia, preparatory to the still brighter day when above shaft, and architrave, and pediment, should soar the matchless dome of Florence, and the heaven-bound spires of Strasbourg and Salisbury. But another element was requisite to this result, and was contributed by the genius of Lombardy. The campanile, bell-tower, or steeple, owes its origin entirely to Christianity amid western barbarians; as such a member was never attached to an idol-temple, and is forbidden still to the proudest mosques of the false prophet. Moreover, unlike the Saracens who never admitted animal forms into decorative construction, the Lombards copiously used it after every type and form. Saints, founders of churches, and legendary heroes were strangely intermixed with all the strange animals of the natural creation, carved in bas-reliefs on walls, capitals, and wherever, within the edifice or without, a void space was found to receive them. When the soaring nave of the Gothic minster supervened upon preceding art, and absorbed it all, then was superadded all the beautiful varieties of vegetable life. In the clustered and banded stalks of its lofty pillars, the crisp leaves of its capitals and corbeled cornices, the interlacing arches of its fretted and embossed vaults, and the interminable complexities of its flowing tracery, were seen traits which comported well with the hues that sparkled from roof and chapter, walls and windows, and which recalled no work of man indeed, no rustic hut or savage cavern, but the sublimest temple of natural religion; the aspiring height of the slender pine, the spreading arms of the giant oak, rich with the varied tints of leaf and blossom, soothing as the rustle of balmy breezes, and melodious with the choral songs of ten thousand birds.