"I can't seem to get a mental grip on it," the Big Business Man declared. "You--" "Think of it this way," Rogers went on earnestly. "Motion can easily change our impression of solidity. This is not an analogous case, perhaps, but it will give you something to think about. Water is normally a fluid. You can pass your hand through a stream of water from a garden hose. But set that water in more rapid motion, and what physical impression do you get? At Fully, Switzerland, water for a turbine emerges from a nozzle at a speed of four hundred miles per hour. What would happen if you tried to pass your hand through that? I have seen a jet no more than three inches in diameter of such rapidly moving water, and you cannot cut through it with the blow of a crowbar! There you have a physical substance--an impression of solidity--derived from motion." "But what has all this to do with time?" the Banker objected, after a moment of silence. "Everything," said Loto quickly. "Since we are changing the time-dimension of matter, without altering its space-dimensions, you must have some conception of what matter really is. When once you realize the real intangibility of even our own bodies, or this house we are in, you will be able to understand us better." The Banker relaxed. "Go on, boy. Let's hear it." "Yes, sir. Changing the time-dimension of substance amounts merely to a change in the rate and character of the motion that constitutes the electrical vortex we call a proton." Loto looked at Rogers somewhat helplessly, with a faintly quizzical smile twitching at his lips. "I seem to be talking very ponderously tonight, father. I wonder if it wouldn't be easier for us to show them the apparatus?" Rogers rose from his chair. "By all means. Gentlemen, Loto has completed his apparatus on the roof of the club. You may have noticed for the past month that one end is boarded up, and has a canvas roof over it. That is where Loto has been working. Will you come up with us?" The building that houses the New York Scientific Club is a full block in depth and twenty stories high. Its flat roof is surrounded by a parapet of stone. One end of the roof is a garden, with pergolas, trellised vines, and beds of flowers with white gravel walks between. At the other end, on this particular evening, a twenty-foot, rough board wall enclosed a space about a hundred feet square, with a canvas roof above it.