In pure art the Romans merely copied the Greeks, but they developed bronze casting techniques that were capable of producing every facial detail on their bronze figures. Heads of these figures have been found in the temples, in river mud and in other localities where anything but bronze or copper would have corroded long ago.
As an essentially practical nation, the Romans were great builders and engineers. Neither time nor siege, nor natural catastrophes, has destroyed their solid stonework. Roman stone structures were not infrequently held together by copper or bronze ties and clamps and they made more use than the Greeks of copper and bronze in their important buildings: but here again the hands of the spoiler and the pockets of the needy have melted down most of the evidence.
The finest surviving architectural work of this type is the Pantheon at Rome, an immense circular temple 143 ft in diameter which is surmounted by a dome of 140 ft. The dome had an open hole, or cella, 30 ft across at its apex which provided the only light to the interior. This dome was originally covered with copper plates with an outside covering of copper or bronze tiles; but only the central ring now remains. The tiles were stolen by Constans II in A.D. 663, and carried off to Constantinople, but were captured by the Saracens en route. Almost a thousand years afterwards Pope Urban VIII removed the copper plates from the roof, an act which yielded him 200 tons of copper sheets, in addition to four tons of copper nails.
During the great days of the Early Empire, when the wealth of the world lay at their feet, the Romans spared nothing in the way of luxury or decoration. Their temples had bronze doors and the vestibules were sometimes enclosed by bronze grilles; but only the great bronze doors of the Pantheon still remain unmelted.