Turning back and passing across the Campus we arrive at the public baths erected by Nero, and then at the Pantheon. This building, though shorn of many of its decorative splendours both within and without, still stands structurally intact, at least as it was restored and enlarged two generations later than our date. It is scarcely possible to say how far its shape was altered at its restoration under Hadrian, but we may provisionally treat the edifice as already belonging to our period. It is still, after all these centuries, an entirely noble pile, and forms a fit receptacle for the tomb, not only of Victor Emanuel, but of Raphael. Its form is that of a rotunda, with walls of concrete 20 feet in thickness and with a dome of concrete cast in a solid mass. The middle of the dome is open to the sky, and by that means the building is lighted in a manner most perfectly suited to it. Could we behold it fully restored and at its best, we should see above its portico, which is supported by huge marble pillars each made of a single stone, large bronze reliefs of gods and giants. To one side of the doors would be a colossal statue of Augustus; on the other a colossal statue of the builder Agrippa, the son-in-law of that emperor. Inside there is a series of niches for colossal effigies of Mars, Venus, and other deities connected with the Julian family. The marble pillars dividing the niches have capitals of fine bronze, and the coffered ceiling of the dome, now bare and colourless, shines with gilt on blue, like the sky lit up with stars. The doors, which have mysteriously remained entire, are also of noble bronze; the roof consists of tiles of bronze thinly plated with gold. The gold has naturally vanished, after passing into Saracen hands; of the bronze nearly half a million pounds weight has been stripped from the building, some to make cannon for the defence of the Castle of St. Angelo, some to form the twisted columns which now support the giant baldacchino under St. Peter's dome.