“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?”