Van Manderpootz pointed to the headpiece. "Put it on," he said, and I sat staring at the screen of the psychomat. I suppose everyone is familiar with the Horsten psychomat; it was as much a fad a few years ago as the ouija board a century back. Yet it isn't just a toy; sometimes, much as the ouija board, it's a real aid to memory. A maze of vague and colored shadows is caused to drift slowly across the screen, and one watches them, meanwhile visualizing whatever scene or circumstances he is trying to remember. He turns a knob that alters the arrangement of lights and shadows, and when, by chance, the design corresponds to his mental picture—presto! There is his scene re-created under his eyes. Of course his own mind adds the details. All the screen actually shows are these tinted blobs of light and shadow, but the thing can be amazingly real. I've seen occasions when I could have sworn the psychomat showed pictures almost as sharp and detailed as reality itself; the illusion is sometimes as startling as that.

Van Manderpootz switched on the light, and the play of shadows began. "Now recall the circumstances of, say, a half-year after the market crash. Turn the knob until the picture clears, then stop. At that point I direct the light of the subjunctivisor upon the screen, and you have nothing to do but watch."