a short inscription in printed Roman capitals, thus:
“THE PICKERDILLEY STUF IS UP THE CHIMBLY 416 WARDOUR ST 2ND FLOUR BACK IT WAS HID BECOS OF OLD MOAKEYS JOOD MOAKEY IS A BLITER.”
“Then that fellow wasn’t an anarchist at all?” I exclaimed.
“No,” said Miller. “He was one of Moakey’s gang. We suspected Moakey of being mixed up with that job, but we couldn’t fix it on him. By Jove!” he added, slapping his thigh, “if this is right, and I can lay my hands on the loot! Can you lend me a bag, doctor? I’m off to Wardour Street this very moment.”
We furnished him with an empty suitcase, and, from the window, watched him making for Mitre Court at a smart double.
“I wonder if he will find the booty,” said Thorndyke. “It just depends on whether the hiding-place was known to more than one of the gang. Well, it has been a quaint case, and instructive, too. I suspect our friend Barton and the evasive Schönberg were the collaborators who produced that curiosity of literature.”
“May I ask how you deciphered the thing?” I said. “It didn’t appear to take long.”
“It didn’t. It was merely a matter of testing a hypothesis; and you ought not to have to ask that question,” he added, with mock severity, “seeing that you had what turn out to have been all the necessary facts, two days ago. But I will prepare a document and demonstrate to you tomorrow morning.”
* * * *
“So Miller was successful in his quest,” said Thorndyke, as we smoked our morning pipes after breakfast. “The ‘entire swag,’ as he calls it, was ‘up the chimbly,’ undisturbed.”
He handed me a note which had been left, with the empty suitcase, by a messenger, shortly before, and I was about to read it when an agitated knock was heard at our door. The visitor, whom I admitted, was a rather haggard and dishevelled elderly gentleman, who, as he entered, peered inquisitively through his concave spectacles from one of us to the other.
“Allow me to introduce myself, gentlemen,” said he. “I am Professor Poppelbaum.”
Thorndyke bowed and offered a chair.
“I called yesterday afternoon,” our visitor continued, “at Scotland Yard, where I heard of your remarkable decipherment and of the convincing proof of its correctness. Thereupon I borrowed the cryptogram, and have spent the entire night in studying it, but I cannot connect your solution with any of the characters. I wonder if you would do me the great favour of enlightening me as to your method of decipherment, and so save me further sleepless nights? You may rely on my discretion.”
“Have you the document with you?” asked Thorndyke.
The Professor produced it from his pocket-book, and passed it to my colleague.
“You observe, Professor,” said the latter, “that this is a laid paper, and has no water-mark?”
“Yes, I noticed that.”
“And that the writing is in indelible Chinese ink?”
“Yes, yes,” said the savant impatiently; “but it is the inscription that interests me, not the paper and ink.”
“Precisely,” said Thorndyke. “Now, it was the ink that interested me when I caught a glimpse of the document three days ago. ‘Why,’ I asked myself, ‘should anyone use this troublesome medium’—for this appears to be stick ink—‘when good writing ink is to be had?’ What advantages has Chinese ink over writing ink? It has several advantages as a drawing ink, but for writing purposes it has only one: it is quite unaffected by wet. The obvious inference, then, was that this document was, for some reason, likely to be exposed to wet. But this inference instantly suggested another, which I was yesterday able to put to the test—thus.”
He filled a tumbler with water, and, rolling up the document, dropped it in. Immediately there began to appear on it a new set of characters of a curious grey colour. In a few seconds Thorndyke lifted out the wet paper, and held it up to the light, and now there was plainly visible an inscription in transparent lettering, like a very distinct water-mark. It was in printed Roman capitals, written across the other writing, and read:
“THE PICKERDILLEY STUF IS UP THE CHIMBLY 416 WARDOUR ST 2ND FLOUR BACK IT WAS HID BECOS OF OLD MOAKEYS JOOD MOAKEY IS A BLITER.”
The Professor regarded the inscription with profound disfavour.
“How do you suppose this was done?” he asked gloomily.
“I will show you,” said Thorndyke. “I have prepared a piece of paper to demonstrate the process to Dr. Jervis. It is exceedingly simple.”
He fetched from the office a small plate of glass, and a photographic dish in which a piece of thin notepaper was soaking in water.
“This paper,” said Thorndyke, lifting it out and laying it on the glass, “has been soaking all night, and is now quite pulpy.”
He spread a dry sheet of paper over the wet one, and on the former wrote heavily with a hard pencil, “Moakey is a bliter.” On lifting the upper sheet, the writing was seen to be transferred in a deep grey to the wet paper, and when the latter was held up to the light the inscription stood out clear and transparent as if written with oil.
“When this dries,” said Thorndyke, “the writing will completely disappear, but it will reappear whenever the paper is again wetted.”
The Professor nodded.
“Very ingenious,” said he—“a sort of artificial palimpsest, in fact. But I do not understand how that illiterate man could have written in the difficult Moabite script.”
“He did not,” said Thorndyke. “The ‘cryptogram’ was probably written by one of the leaders of the gang, who, no doubt, supplied copies to the other members to use instead of blank paper for secret communications. The object of the Moabite writing was evidently to divert attention from the paper itself, in case the communication fell into the wrong hands, and I must say it seems to have answered its purpose very well.”
The Professor started, stung by the sudden recollection of his labours.
“Yes,” he snorted; “but I am a scholar, sir, not a policeman. Every man to his trade.”
He snatched up his hat, and with a curt “Good-morning,” flung out of the room in dudgeon.
Thorndyke laughed softly.
“Poor Professor!” he murmured. “Our playful friend Barton has much to answer for.”
THE MANDARIN’S PEARL (1909)
Mr. Brodribb stretched out his toes on the kerb before the blazing fire with the air of a man who is by no means insensible to physical comfort.
“You are really an extraordinarily polite fellow, Thorndyke,” said he.
He was an elderly man, rosy-gilled, portly, and convivial, to whom a mass of bushy, white hair, an expansive double chin, and a certain prim sumptuousness of dress imparted an air of old-world distinction. Indeed, as he dipped an amethystine nose into his wine-glass, and gazed thoughtfully at the glowing
