the facts. Your chemical lecturers—you may go downstairs now and ask, if you disbelieve me—always cheat over the indestructibility of matter experiment—always. And then another—a physiography thing. You know the experiment I mean? To demonstrate the existence of the earth's rotation. They use—they use—"
"Foucault's pendulum," said Lewisham. "They use a rubber ball with a pin-hole hidden in the hand, and blow the pendulum round the way it ought to go."
"But that's different," said Smithers.
"Wait a moment," said Lagune, and produced a piece of folded printed paper from his pocket. "Here is a review from Nature of the work of no less a person than Professor Greenhill. And see—a convenient pin is introduced in the apparatus for the demonstration of virtual velocities! Read it—if you doubt me. I suppose you doubt me."
Smithers abruptly abandoned his position of denial "in toto." "This isn't my point, Mr. Lagune; this isn't my point," he said. "These things that are done in the lecture theatre are not to prove facts, but to give ideas."
"So was my demonstration," said Lagune.
"We didn't understand it in that light."
"Nor does the ordinary person who goes to Science lectures understand it in that light. He is
