Very truly yours,
Peter Merton
He folded it and put it in the safe. Then he sat down and watched it. He watched it for fifteen minutes before he decided that nothing was going to happen. Finally, he walked over and took out the paper. It was the same as it had been when he put it in.
He looked back at the plastic sheet. Aha! It said: "In order for the Time Transfer Field to work, it must be surrounded entirely by thick metal."
He put the note back in, and this time he closed and locked the door.
Three minutes later, he opened it again. This time, there was another folded sheet of plastic. It said:
Dear Mr. Merton:
Understanding Time Transfer is very simple. Of course, the science of your time would be unable to build such a machine, but what happens is essentially this: If you put something in your metal box, we can pick it up and bring it to our time. However, there must be an equivalent exchange of matter, so we have to send something to your century, too. This must be done in accordance with the Law of Entropy.
What we need mostly are historical documents; newspapers, books, and magazines of your era. Please send only factual material; no fiction. We will want fiction later, but not now.
Here is a list of things we would like to have.