"Is it?" interrupted Arden with a smile. "What happens to radiation when intercepted?" "Turns to heat, of course." "That takes care of the radiation output," said Arden. "Now, how about electrical losses?" "Also heat." "Then everything that goes into an electric heater emerges as heat," said Arden. "I get it," laughed Walt. "Efficiency depends upon what you hope to get. If what you're wanting is losses, anything that is a total loss is one hundred percent efficient. Set your machine up to waste power and it becomes one hundred percent efficient as long as there is nothing coming from the machine that doesn't count as waste." "Fine point for argument," smiled Channing. "But anything that will make atmosphere glow that dull red after the passage of a ship will have enough waste to detect. Don't tell me that the red glow enhances the drive." The door opened again and Charley came in with a crew of men. They ignored the three, and started to hang heavy cloth around the walls and ceiling. Charley watched the installation of the barrier-cloth and then said: "Beat it--if you want any young Channings!" Arden, at least, had the grace to blush. * * * * * The tall, slender man handed Don an envelope full of credentials. "I'm Wesley Farrell," he said. "Glad to have a chance to work out here with you fellows." "Glad to have you," said Don. He looked at the other man. "This is Mark Kingman." "How do you do?" said Channing. Kingman did not impress Channing as being a person whose presence in a gathering would be demanded with gracious shouts of glee. "Mr. Kingman is an attorney for Terran Electric," explained Wesley. Kingman's pedestal was lowered by Channing. "My purpose," said Kingman, "is to represent my company's interest in the transmission tube." "In what way?" asked Don. "Messrs. Baler and Carroll sold their discovery to Terran Electric outright. We have an iron-bound patent on the device and/or any developments of the device. We hold absolute control over the transmission tube, and therefore may dictate all terms on which it is to be used." "I understand. You know, of course, that our interest in the transmission tube is purely academic." "I have been told that. We're not too certain that we approve. Our laboratories are capable of any investigation you may desire, and we prefer that such investigations be conducted under our supervision." "We are not going to encroach on your power rights," explained Channing. "Naturally," said Kingman in a parsimonious manner. "But should you develop a new use for the device, we shall have to demand that we have complete rights." "Isn't that a bit high-handed?" asked Don. "We think not. It is our right." "You're trained technically?" asked Don. "Not at all. I am a lawyer, not an engineer. Mr. Farrell will take care of the technical aspects of the device." "And in looking out for your interests, what will you require?"