"It has been said that the surface of the island throughout was overlaid or paved with stones. The depth of these was not great, possibly not more than from 1 to 2 feet, there not being in any part that became visible more than two courses. Wood ashes were discovered on the surface--a portion being also found a little below, and some of the stones at one part, in particular the fragments of a sandstone flag, bore distinct evidence of the action of fire; and it was supposed that this flag might have been the hearth of some structure reared on the surface. These stones are to be held as the uppermost artificial stratum. The next in descent was a layer of large coarse water-borne gravel mixed with finer sand, which was of the depth of from 18 inches to 2 feet. The third layer was brushwood, boughs of trees, among which the hazel predominated, ferns, etc. etc., but the whole was so compressed as not to manifest a greater depth than about 6 inches. The fourth layer was beams or logs of wood, some of which were nearly 2 feet in diameter, although the greater number was less. These seemed laid down horizontally, and so as to cross or intersect each other, similar to a raft of wood; some of them showed that they had been mortised or checked into each other, or into vertical piles, and that the tenons when inserted had been fastened by wooden pins, and in one or two instances by large iron nails. "The whole of this wood-work, however, when exposed, was in a greatly disturbed and loosened condition from the movement and upheaval of the structure; and, in consequence, what space in depth these cross-beams occupied was not ascertainable. Then the fifth and lowest stratum was the underlying mud, which was fine, pure, and free of stones, and not at all like boulder clay. Besides, there was manifested as having been planted on the surface, one if not more wooden structures, houses or huts they might be, small in size, and one of which at least was in the form of a parallelogram, having been constructed of small round posts of wood used in forming the sides and ends. How it had been roofed did not appear. There were seen also bits of bone, as those of birds, as well as a few teeth, similar to those of the cow or ox. Trees, for the most part of a low stature, were over all parts, as well as reeds and other coarse grasses which sprang up between the stones on the surface.