Dorothy heaved a sigh of relief. She bent forward and kissed Tom in the full face of the assembly.
“Tom, you’re the finest, best man in the world, except one.”
“That’s it,” said Tom with a grin. “Second place for old uncle Thomas now.”
“But Tom,” I said, “I follow the boat construction all right, but for Heaven’s sake what is this caema that I’ve heard so much about, and what’s the use of the cage?”
“Oh, I forgot you might not understand that,” said Tom. “You know, or you ought to know, it’s in every school physics, that if you put a cage of a conductor like copper around any instrument which is easily affected by any electrical discharge, the electrical waves spread out, follow the surface of the cage, and don’t penetrate the interior. The instrument is wholly unaffected. Well, caema is the newest organic conductor. It acts the same way with any radio-active waves. They spread out all over it, and can’t get through. I’ve had a cage built of it to insulate you and everything else that’s inside.”
“Why wouldn’t it work around the battleships then?” I asked.
“Because the battleships are made of steel; and if you put a cage like that around them, they could hardly move. It only worked on your boat because it’s wood outside.”
“Tom,” I said gravely, “I imagine your forethought and knowledge will save my life.”
“I know it will,” said Tom cheerfully. “Now, what time do you leave?”
“In fifty-five minutes, from Charing Cross, on the Channel Express,” I said.