Joe said sombrely, "Something's got to be done about space ships before that comes up again!"
Somebody appeared with a tray. There was food on it. Smoking hot food. Joe looked at it and knew that his appetite, anyhow, was back to Earth normal.
"Thanks!" he mumbled appreciatively, and attacked the food.
Mike drank his coffee. Then he said, "Joe, do you know anything about powder metallurgy?"
Joe shrugged. It hurt. "Powder metallurgy? Yes, I've seen it used, at my father's plant. They've made small precision parts with it. Why?"
"D'you know if anybody ever made a weld with it?" asked Mike.
"I think so. Yes. At the plant they did. They had trouble getting the surfaces properly cleaned for welding. But they managed it. Why?"
"One more question," said Mike tensely. "How much Portland cement is used to make a cubic yard of concrete?"
"I wouldn't know," admitted Joe. "Why? What's all this about?"