human
Remember this, Dick? he asked.
gpt
It's the thing I spoke of that I forgot until I came across it in my pocket this morning.
human
What is it, Harry?
gpt
Don't you remember that we watched them heliographing some messages, and put down the Morse signs? Here they are. Now the thing to do is to see if we can't work out the meaning of the code. If it's a code that uses words for phrases we're probably stuck, but I think it's more likely to depend on inversions.
human
What do you mean, Harry? asked Jack.
gpt
I'm sorry I don't know anything about codes and ciphers.
human
Why, there are two main sorts of codes, Jack, and, of course, thousands of variations of each of those principal kinds. In one kind the idea is to save words--in telegraphing or cabling. So the things that are likely to be said are represented by one word. For instance _Coal_, in a mining code, might mean 'Struck vein at two hundred feet level.' In the other sort of code, the letters are changed. That is done in all sorts of ways, and there are various tricks. The way to get at nearly all of them is to find out which letter or number or symbol is used most often, and to remember that in an ordinary letter E will appear almost twice as often as any other letter--in English, that is.
gpt
But won't this be in German?
human
Yes. That's just why I wanted those names Dick heard. They are likely to appear in any message that was sent. So, if we can find words that correspond in length to those, we may be able to work it out. Here goes, anyhow!