Tubby shook hands. “Mine’s Tubby,” he said. “Pleased to meet you.” The professor put on his high hat, which made him nearly as tall as Tubby. “I want to consult you on a matter of very great importance to both of us,” he said slowly. Tubby waited. “About light,” the professor added. He linked his arm in Tubby’s confidentially. “I need your help. They tell me you’re the smartest man in town. I wanted to find you. With a brain like yours and mine—” “Yes,” said Tubby breathlessly, when the professor paused. “My laboratory’s right across the street,” said the little man. “I’ll show you.” Tubby followed the professor out of the theater, through a little doorway across the street and up several flights of rickety stairs into a room on the top floor of the house. “This is where I work,” said the professor. “Sit down.” It was a large room with endless row of bottles upon tiers of shelves lining its walls. Several long tables stood about, and Tubby saw they were crowded with curious apparatus—little tubes in racks, microscopes, triangular pieces of glass with candles behind them, and several contrivances of wheels and weights that looked like clock works. In the exact center of the room was one larger apparatus of a sort Tubby had never seen before; it seemed very complicated and he stared at it with awe. He could make nothing out of it except that part of it was a huge telescope, extending up through the skylight of the room. He glanced upward, and there, through a narrow, open slit in the glass, he could see the stars shining. “That’s a Light Machine,” said the professor, following his glance. “There’s only one in the world, and there it is.” “Yes,” said Tubby. “It’s the most wonderful machine that was ever built,” the professor went on softly. “I built it; and now _you_ are going to help me make money out of it.” “Yes,” said Tubby. “How?” “That’s what _you_ are going to tell _me_. Don’t you see? I am a man of science—you are a business man. That’s the difference between us.” “Yes,” said Tubby. “First I’ll have to explain. You have a head for figures, of course?” “No—yes,” said Tubby. “Of course.” “But you don’t know much about light?” “Yes—no,” said Tubby. “Naturally. How could you. Nobody does—but me. And I know all about it—_all_.” He emphasized the last word impressively. “And now I’m going to tell it to you.” “Thank you very much,” said Tubby, and waited. “All my life,” began the professor—he spoke softly; his eyes, fixed on Tubby seemed staring at dim, distant spaces—“all my life—since I was a little boy—I have been studying the properties of light. It is a very wonderful thing—you realize that, do you not—the most wonderful thing in the whole of science?” “Oh, yes,” said Tubby. The professor drew in a deep breath, like a long sigh reversed. “Light,” he began again, “is a vibratory wave in the Ether. You know what the Ether is?” “No,” said Tubby.