How far the grand gallery corresponds with these requirements can be judged from the following description given by Professor Greaves in 1638:--"It is," he says, "a very stately piece of work, and not inferior, either in respect of the curiosity of art, or richness of materials, to the most sumptuous and magnificent buildings," and a little further on he says, "this gallery, or corridor, or whatever else I may call it, is built of white and polished marble (limestone), the which is very evenly cut in spacious squares or tables. Of such materials as is the pavement, such is the roof and such are the side walls that flank it; the coagmentation or knitting of the joints is so close, that they are scarce discernible to a curious eye; and that which adds grace to the whole structure, though it makes the passage the more slippery and difficult, is the acclivity or rising of the ascent. The height of this gallery is 26 feet" (Professor Smyth's careful measurements show the true height to be more nearly 28 feet), "the breadth of 6.870 feet, of which 3.435 feet are to be allowed for the way in the midst, which is set and bounded on both sides with two banks (like benches) of sleek and polished stone; each of these hath 1.717 of a foot in breadth, and as much in depth." These measurements are not strictly exact. Smyth made the breadth of the gallery above the banks or ramps as he calls them, 6 feet 10-1/5 inches; the space between the ramps, 3 feet 6 inches; the ramps nearly about 1 foot 8-1/14 inches broad, and nearly 1 foot 9 inches high, measured transversely, that is at right angles to the ascending floor. As to arrangements for the convenience of observers in the slippery and difficult floor of this gallery, we find that upon the top of these benches or ramps, near the angle where they meet the wall, "there are little spaces cut in right-angled parallel figures, set on each side opposite one another, _intended no question for some other end than ornament_."