"Perhaps there are points which have escaped your Machiavellian intellect. Let us consider the problem in the light of pure reason. This man's reference is to a book. That is our point of departure."
"A somewhat vague one."
"Let us see then if we can narrow it down. As I focus my mind upon it, it seems rather less impenetrable. What indications have we as to this book?"
"Well, well, it is surely not quite so bad as that. The cipher message begins with a large 534, does it not? We may take it as a working hypothesis that 534 is the particular page to which the cipher refers. So our book has already become a large book which is surely something gained. What other indications have we as to the nature of this large book? The next sign is C2. What do you make of that, Watson?"
"Chapter the second, no doubt."
"Hardly that, Watson. You will, I am sure, agree with me that if the page be given, the number of the chapter is immaterial. Also that if page 534 finds us only in the second chapter, the length of the first one must have been really intolerable."
"Column!" I cried.
"Brilliant, Watson. You are scintillating this morning. If it is not column, then I am very much deceived. So now, you see, we begin to visualize a large book printed in double columns which are each of a considerable length, since one of the words is numbered in the document as the two hundred and ninety- third. Have we reached the limits of what reason can supply?"
"I fear that we have."
"Surely you do yourself an injustice. One more coruscation, my dear Watson -- yet another brain-wave! Had the volume been an unusual one, he would have sent it to me. Instead of that, he had intended, before his plans were nipped, to send me the clue in this envelope. He says so in his note. This would seem to indicate that the book is one which he thought I would have no difficulty in finding for myself. He had it -- and he imagined that I would have it, too. In short, Watson, it is a very common book."
"What you say certainly sounds plausible."
"So we have contracted our field of search to a large book, printed in double columns and in common use."
"The Bible!" I cried triumphantly.
"Good, Watson, good! But not, if I may say so, quite good enough! Even if I accepted the compliment for myself I could hardly name any volume which would be less likely to lie at the elbow of one of Moriarty's associates. Besides, the editions of Holy Writ are so numerous that he could hardly suppose that two copies would have the same pagination. This is clearly a book which is standardized. He knows for certain that his page 534 will exactly agree with my page 534."
"But very few books would correspond with that."
"Exactly. Therein lies our salvation. Our search is narrowed down to standardized books which anyone may be supposed to possess."
"There are difficulties, Watson. The vocabulary of Bradshaw is nervous and terse, but limited. The selection of words would hardly lend itself to the sending of general messages. We will eliminate Bradshaw. The dictionary is, I fear, inadmissible for the same reason. What then is left?"
"Excellent, Watson! I am very much mistaken if you have not touched the spot. An almanac! Let us consider the claims of Whitaker's Almanac. It is in common use. It has the requisite number of pages. It is in double column. Though reserved in its earlier vocabulary, it becomes, if I remember right, quite garrulous towards the end." He picked the volume from his desk. "Here is page 534, column two, a substantial block of print dealing, I perceive, with the trade and resources of British India. Jot down the words, Watson! Number thirteen is 'Mahratta.' Not, I fear, a very auspicious beginning. Number one hundred and twenty-seven is 'Government'; which at least makes sense, though somewhat irrelevant to ourselves and Professor Moriarty. Now let us try again. What does the Mahratta government do? Alas! the next word is 'pig's-bristles.' We are undone, my good Watson! It is finished!"
He had spoken in jesting vein, but the twitching of his bushy eyebrows bespoke his disappointment and irritation.