[43] Vessels with two, or three, or four rows of oars.
[45] Every square yard of this part of Rome has been trenched in the search for statues in the seventeenth and eighteenth centuries, and records of these numerous excavations are carefully preserved in the Miscellanea of Fea. Had there been any such building as would be required for this purpose anywhere near his palace, it must have come to light, and nothing of the kind has been found.
[47] The basin of Nero was possibly cut through the layer of tufa, which underlies the whole soil of Rome, down to the clay under it. In some excavations made under my direction in a cave under the Aventine, near the Marmorata, which was the mouth of the Aqua Appia, a level bed of white clay was found under the tufa rock of which the Aventine Hill consists; this would account for the walls in the central part built of concrete and brick, on this clay foundation, having been frequently damaged by earthquakes, while the great stone arcades, being built upon the tufa rock, did not suffer from the shocks. Clay is always a bad foundation to build upon, and there are always settlements in buildings that rest upon it. The objection to this theory is, that the surface of the water would be twenty-one feet below the arena and the foot of the podium.
[49] In the ancient catalogue of the Emperors and their works, known as “Catalogus Viennensis Imp. Rom. apud Eccard.,” under Vespasian, it is stated that he dedicated the first three steps of the amphitheatre, implying that three were already finished even in his time.
[A.D. 70.] “Hic prior tribus gradibus amphitheatrum dedicavit;”
That Titus added two more.
[A.D. 81.] “Hic amphitheatrum a tribus gradibus patris sui dura adjecit.”