We may distinguish on the pavement marks of the openings of the doors, consisting of grooves forming portions of circles, which have probably received plates of metal. The centre from which these segments are described, is, as has been already mentioned, clear of the thickness of the walls. It is doubtful if there were originally any opening between this chamber and the cell of the temple. If such existed, it was probably a small side door, but a large central doorway doubtless existed here while the building was occupied as a church. Stuart has remarked a sinking round the larger space which formed the hypæthral cell of the temple, at the distance of 15 feet from the walls; but he has not noticed some peculiarities in the pavement, which are of considerable importance in understanding the construction and arrangement of the building. There is first a pavement of marble slabs, 8 inches thick, as in the opisthodomus, 10 feet 3 inches and a half wide at the end, and not quite so much at the side: next to this is a course 4 feet wide, and 14 inches thick, doubtless intended to receive the columns of the internal peristyle. At one angle of the parallelogram, formed by this series of slabs, there are faint traces of the position of a column about 3 feet 9 inches in diameter, and as these blocks are regularly spaced, we may ascertain that the distance from centre to centre of the columns was about 11 feet 6 inches, and consequently the space between them was 7 feet 9 inches, while in the other intervals, the space from centre to centre was 12 feet 11 inches, and the clear intercolumniation about 9 feet 2 inches. The ancients always placed the internal columns, and those of their courts, proportionally farther apart than the external ones. At Pæstum, where the outer columns are only one and a tenth diameter apart, the inner are nearly one and two fifths; at Egina, those of the external peristyle are about one diameter and two thirds asunder, those of the internal, two and one third. In the Propylæa, the spaces between the external columns seem to be about one diameter and a half, if we exclude the large middle entrance, the internal about two and a half. In the latter case, the internal columns were Ionic, and it is very possible that this was also the case in the Parthenon, but we have not the slightest fragment remaining; a circumstance which seems to me very remarkable. Was no use made of them in the church? and if so, why were they rejected?