“I—­I don’t believe it is going to be so very difficult to translate them.”

“Great guns!” said the Captain.  “Do you mean to say that you can ultimately translate that cipher?”

The Tracer smiled.  “Let’s examine it for repetitions first.  Here we have this symbol

[Illustration:  Cryptographic symbol]

repeated five times.  It’s likely to be the letter E. I think—­” His voice ceased; for a quarter of an hour he pored over the symbols, pencil in hand, checking off some, substituting a letter here and there.

“No,” he said; “the usual doesn’t work in this case.  It’s an absurdly simple cipher.  I have a notion that numbers play a part in it—­you see where these crossed squares are bracketed—­those must be numbers requiring two figures—­”

He fell silent again, and for another quarter of an hour he remained motionless, immersed in the problem before him, Harren frowning at the paper over his shoulder.

CHAPTER X

“Come!” said the Tracer suddenly; “this won’t do.  There are too few symbols to give us a key; too few repetitions to furnish us with any key basis.  Come, Captain, let us use our intellects; let us talk it over with that paper lying there between us.  It’s a simple cipher—­a childishly simple one if we use our wits.  Now, sir, what I see repeated before us on this sheet of paper is merely one of the forms of a symbol known as Solomon’s Seal.  The symbol is, as we see, repeated a great many times.  Every seal has been dotted or crossed on some one of the lines composing it; some seals are coupled with brackets and armatures.”

[Illustration:  Cryptographic symbol]

“What of it?” inquired Harren vacantly.

“Well, sir, in the first place, that symbol is supposed to represent the spiritual and material, as you know.  What else do you know about it?”

[Illustration:  Cryptographic symbol]

“Nothing.  I bought a book about it, but made nothing of it.”

“Isn’t it supposed,” asked Mr. Keen, “to contain within itself the nine numerals, 1, 2, 3, 4, 5, 6, 7, 8, 9, and even the zero symbol?”

“I believe so.”

“Exactly.  Here’s the seal

[Illustration:  Cryptographic symbol]

Now I’ll mark the one, two, and three by crossing the lines, like this: 

one,

[Illustration:  Cryptographic symbol]

two,

[Illustration:  Cryptographic symbol]

three,

[Illustration:  Cryptographic symbol]

Now, eliminating all lines not crossed there remains

the one,

[Illustration:  Cryptographic symbol]

the two,

[Illustration:  Cryptographic symbol]

the three,

[Illustration:  Cryptographic symbol]

And here is the entire series: 

[Illustration:  Cryptographic symbols]