So much for the movements. But how about the raps? How about those mysterious tappings which come from the very heart of the table, as eloquent of the preternatural as those immortal taps heard by Poe ere the raven stepped into his chamber? I should be more impressed by these taps if I were not capable of manufacturing them myself _ad lib._ without detection, by secretly manipulating the ball of my thumb. One is therefore justified in assuming that, where these raps are not produced by conscious fraud, they are the involuntary result of the same motions that produced them voluntarily. Even wood has a certain elasticity, and an imperceptible increase followed by an imperceptible relaxation of pressure on the surface of the table will alter the tension of the wood, the molecules of which in springing back to their prior position will emit a creak or a tap, just as a piece of extended elastic will when let go again. Both the raps and the movements, then, are in essence phenomena of the same order: simple results of muscular pressure, conscious, sub-conscious, or unconscious. It now only remains to explain the answers themselves, to account not only for their almost invariably logical form, but also for their occasionally astonishing content. For the table is not infrequently wiser than anybody in the room; also it knows the past and is ready to predict the future. The whole thing is really an excellent object-lesson in Psychology. For the solution is obvious. The table being unconscious, _you answer yourself_--you not only produce the raps and movements, but you regulate them.