“She’s got to quit this sort of thing,” he said savagely and apropos of nothing, as we walked along. “It’s hard on her, and besides—”

“Yes?”

“She couldn’t have learned about it,” he said, following his own trail of thought. “My car brought her from her home to the house-door. She was brought in to us at once. But don’t you see that if there are other developments, to prove her statements she—well, she’s as innocent as a child, but take Herbert, for instance. Do you suppose he’ll believe she had no outside information?”

“But it was happening while we were shut in the drawing-room.”

“So Elinor claims. But if there was anything to hide, it would have taken time. An hour or so, perhaps. You can see how Herbert would jump on that.”

We went back, I remember, to speaking of the seance itself, and to the safer subject of the physical phenomena. As I have said, we did not then know of those experimenters who claim that the medium can evoke so-called rods of energy, and that by its means the invisible “controls” can perform their strange feats of levitation and the movement of solid bodies. Sperry touched very lightly on the spirit side.

“At least it would mean activity,” he said. “The thought of an inert eternity is not bearable.”

He was inclined, however, to believe that there were laws of which we were still in ignorance, and that we might some day find and use the fourth dimension. He seemed to be able to grasp it quite clearly. “The cube of the cube, or hypercube,” he explained. “Or get it this way: a cone passed apex-downward through a plane.”

“I know,” I said, “that it is perfectly simple. But somehow it just sounds like words to me.”

“It’s perfectly clear, Horace,” he insisted. “But remember this when you try to work it out; it is necessary to use motion as a translator of time into space, or of space into time.”