The effect of the Pantheon is totally the reverse of that of St. Peter’s. Though not a fourth part of the size, it is, as it were, the visible image of the universe; in the perfection of its proportions, as when you regard the unmeasured dome of heaven, the idea of magnitude is swallowed up and lost. It is open to the sky, and its wide dome is lighted by the ever-changing illumination of the air. The clouds of noon fly over it, and at night the keen stars are seen through the azure darkness, hanging immoveably, or driving after the driving moon among the clouds. We visited it by moonlight; it is supported by sixteen columns, fluted and Corinthian, of a certain rare and beautiful yellow marble, exquisitely polished, called here _giallo antico_. Above these are the niches for the statues of the twelve gods. This is the only defect of this sublime temple; there ought to have been no interval between the commencement of the dome and the cornice, supported by the columns. Thus there would have been no diversion from the magnificent simplicity of its form. This improvement is alone wanting to have completed the unity of the idea. The fountains of Rome are, in themselves, magnificent combinations of art, such as alone it were worth coming to see. That in the Piazza Navona, a large square, is composed of enormous fragments of rock, piled on each other, and penetrated, as by caverns. This mass supports an Egyptian obelisk of immense height. On the four corners of the rock recline, in different attitudes, colossal figures representing the four divisions of the globe. The water bursts from the crevices beneath them. They are sculptured with great spirit; one impatiently tearing a veil from his eyes; another with his hands stretched upwards. The Fontana di Trevi is the most celebrated, and is rather a waterfall than a fountain; gushing out from masses of rock, with a gigantic figure of Neptune; and below are two river gods, checking two winged horses, struggling up from among the rocks and waters. The whole is not ill-conceived nor executed; but you know not how delicate the imagination becomes by dieting with antiquity day after day. The only things that sustain the comparison are Raphael, Guido, and Salvator Rosa.