rcial
transactions, symbols used by criminals and every species of malefactor.
And every one of them can be solved with time and patience and a little
knowledge of the subject. But this"--he sat looking at it with eyes half
closed--"this is _too_ simple."

"Simple!"

"Very. It's so simple that it's baffling."

"Do you mean to say you are going to be able to find a meaning in
squares and crosses?"

"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."

"