The shells, higher up on this terrace could be traced scaling off in flakes, and falling into an impalpable powder; and on an upper terrace, at the height of 170 feet, and likewise at some considerably higher points, I found a layer
of saline powder of exactly similar appearance, and lying in the same relative position.
If these discoveries had been made after a lapse of sixteen centuries, under a layer
of dust and ashes on a large scale, surely we might hope to meet with similar cases of preservation, after a lapse of three or four years only, under a layer
of dust and ashes on a small scale.
The floor surface "floats" over a layer
of synthetic material, like neoprene pads, with a bottom layer of plywood completing the sandwich.