The excavations of 1810-14 do not seem to have been carried deep enough to show the floor of the hypogæa, and among the principal new objects of antiquarian interest discovered by the recent operations have been some large blocks of travertine sunk in the floor of the passages, and pierced in their centre with large round holes. These holes have evidently been the sockets into which upright posts of some kind were fixed. In some of these sockets a metal lining still remains, and in one of them the remains of a wooden post are said to have been found. Many conjectures as to the purpose of these sockets have been hazarded. They have been imagined to be the points on which revolving doors turned, or the holes into which posts for chaining wild beasts were fixed, or the capstans for the purpose of winding the ropes attached to stage machines. The explanation which appears to me to be the most probable is that they were used for the erection of temporary wooden posts in the same way in which at the present time such movable posts are used in some of the doorways of large houses in Rome, to divide the doorway temporarily into two distinct passages, by attaching a rope to the posts. When long processions had to be marched across the arena it would be necessary, if they were marshalled below, to have the course of the entering processionists and of those returning kept apart by some such device as that of a rope stretched between posts of this kind. A large wooden framework has been found in the central passage, blackened by long exposure to the water. This seems to have been a contrivance for making an inclined plane on which heavy machines could be dragged up from below. Another discovery which has been made is that of two cryptoportici, one of which extends towards the Esquiline and the Thermæ of Titus, and the other opens out from under the eastern end of the longer axis of the Coliseum. A few graffiti of interest representing gladiatorial figures, and some fragments of inscriptions relating to restorations of the building, or to the munificence of those who indulged the public with amphitheatrical exhibitions, have also been found. The mode in which the naval contests mentioned by Dion as having been exhibited in the Coliseum were conducted, cannot be stated with any certainty. They were given by Titus at the dedication of the building and probably before its completion, so that the space now occupied by the hypogæa may then have been filled with water previously to the construction of the dividing walls.