_Rome, August, 1817._ THERE are several churches at Ravenna of the fifth and sixth centuries, a period, whose architectural productions are very rare. At the beginning of the fifth century this city became the capital of the western empire, and as it was also the seat of government of the Ostrogoths, and afterwards of the Exarchs, it must have enjoyed a pretty long period of comparative prosperity, when every thing else was in ruin. Yet we have by no means a long series of dates in these remains. The Empress Galla Placidia, sister of Honorius and Arcadius, seems to have built a good deal between 425 and 450, the year of her death. Afterwards, Theodoric, who reigned here from 492 to 526, embellished the city with the best edifices the times were capable of producing; and the impulse given to architecture seems to have lasted about twenty years after his death. You are indeed shewn a church, San Vittore, which pretends to be of the early part of the fourth century, but what remains of it, even if its history were true, is a mere barn, without character. The interval which elapsed between the first and last of the churches of this period, which still remain tolerably perfect, was not accompanied with any change of style: the ancient basilican form, consisting of three naves, divided by two ranges of columns supporting arches, prevailed in most of them. Above the arches is a high wall with narrow windows, fewer in number than the arches below, and rarely corresponding with them in position: the roof was of timber, and not concealed from view; and the middle nave terminates in a semicircular recess covered with mosaics, forming the apsis. They are much like St. Paul’s at Rome, but on a reduced scale, and with only one range of columns on each side, or perhaps they are rather more like some of the smaller of the ancient churches in that city. Such is the church of the Spirito Santo, built probably early in the sixth century, which owes its name to a tradition, that on this spot, the eleven immediate successors of St. Apollinaris, first bishop of Ravenna, were chosen by the visible agency of the Holy Ghost, which descended on them successively in the form of a dove. The columns here are of beautiful materials, but of bad workmanship. I think not however, worse than those of Constantine’s time. Architecture seems to have lost more in the twenty years between Dioclesian and Constantine, than in the two hundred between the latter emperor and Theodoric; but perhaps I should find, had I the means of a closer investigation, that I had been deceived in attributing to the earliest of these three periods, columns and ornaments which had once formed part of some earlier edifice. If however, we do not observe in the workmanship, any very distinct marks of difference between the productions of the fourth and sixth centuries, we do in the design of