"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.