Page:The Red Triangle.pdf/156

146 Henning gets into a funk, and resolves to send a message of special urgency to his confederate. For that purpose he uses a cypher which the two have agreed upon—the most ingenious cypher I have ever seen used for the purpose. He doesn't wish to make his message any more conspicuous than he need, so he writes his cypher on this scrap of paper and rolls it inside the key—probably another expedient agreed upon in case of necessity. Then the key goes into an envelope, for greater security of the cypher message, and the messenger gets it when Henning is at last released for lunch. What happened to the message we know; and here it is.

"Now I will not weary you with a detailed account of the different ways in which I attacked this cypher, but I will take the shortest possible cut to the true interpretation. A very short examination of the cryptogram shows that while no number is included above 23, the numbers, in their relative frequency, roughly agree with the relative frequency of the corresponding letters of the alphabet, a for 1, b for 2, and so on."

Here I handed Hewitt the pencilled note I had made at the hospital, with letters substituted for the figures, thus:— i, h, n, d, t, r, e, i; o, s, t, 0, c, i, h, e; c, w, 0, 0, e, m, n, s; s, t, 0, 0, 0, 0, f, a; e, t, 0, 0, 0,