facts—to which we may add the surmise that he has recently purchased a second-hand Blickensderfer of the literary form or, at least, fitted with a literary typewheel."
"I don't quite see how you arrive at that," I said, in some surprise.
"It is merely a guess, you know," he replied, "though a probable one. In the first place he is obviously unused to typing, as the numerous mistakes show; therefore he has not had the machine very long. The type is that which is peculiar to the Blickensderfer, and, in one of the mistakes, an asterisk has been printed in place of a letter. But the literary typewheel is the only one that has the asterisk. As to the age of the machine, there are evident signs of wear, for some of the letters have lost their sharpness, and this is most evident in the case of those letters which are the most used—the 'e,' you will notice, for instance, is much worn; and 'e' occurs more frequently than any other letter of the alphabet. Hence the machine, if recently purchased, was bought second-hand."
"But," I objected, "it may not have been his own machine at all."
"That is quite possible," answered Thorndyke, "though, considering the secrecy that would be necessary, the probabilities are in favour of his having bought it. But, in any case, we have here a means of identifying the machine, should we ever meet with it."
He picked up the label and handed it to me, together with his pocket lens.
"Look closely at the 'e' that we have been discussing; it occurs five times; in 'Thorndyke,' in 'Bench,' in 'Inner,' and in 'Temple.' Now in each case you will notice a minute break in the loop, just at the summit. That break corresponds to a tiny dent in the type—caused, probably, by its striking some small, hard object."
"I can make it out quite distinctly," I said, "and it should be a most valuable point for identification."
"It should be almost conclusive," Thorndyke replied, "especially when joined to other facts that would be elicited by a search of his premises. And now let us just recapitulate the facts which our friend X has placed at our disposal.
"First: X is a person concerning whom I possess certain exclusive information.
"Second: He has some knowledge of my personal habits.
"Third: He is a man of some means and social position.
"Fourth: He is a man of considerable knowledge, ingenuity and mechanical skill.
"Fifth: He has probably purchased, quite recently, a second-hand 'Blick' fitted with a literary typewheel.
"Sixth: That machine, whether his own or some other person's property, can be identified by a characteristic mark on the small 'e.'
"If you will note down those six points and add that X is probably an expert cyclist and a fairly good shot with a rifle, you may possibly be able, presently, to complete the equation, X = ?"
"I am afraid," I said, "I do not possess the necessary data; but I suspect you do, and if it is so, I repeat that it is your duty to society—to say nothing of your clients, whose interests would suffer by your death—to have this fellow laid by the heels before he does any mischief."
"Yes; I shall have to interfere if he becomes really troublesome, but I have reasons for wishing to leave him alone at present."
"You do really know who he is, then?"
"Well, I think I can solve the equation that I have just offered to you for solution. You see, I have certain data, as you suggest, which you do not possess. There is, for instance, a certain ingenious gentleman concerning whom I hold what I believe to be exclusive information, and my knowledge of him does not make it appear unlikely that he might be the author of these neat little plans."
"I am much impressed," I said, as I put away my notebook, after having jotted down the points that Thorndyke had advised me to consider—"I am much impressed by your powers of observation and your capacity for reasoning from apparently trivial data; but I do not see, even now, why you viewed that cigar with such immediate and decided suspicion. There was nothing actually to suggest the existence of poison in it, and yet you seemed to form the suspicion at once and to search for it as though you expected to find it."
"Yes," replied Thorndyke; "to a certain extent you are right. The idea of a poisoned cigar was not new to me—and thereby hangs a tale."
He laughed softly and gazed into the fire with eyes that twinkled with quiet amusement. "You have heard me say," he resumed, after a short pause, "that when I first took these chambers I had practically nothing to do. I had invented a new variety of medico-legal practice and had to build it up by slow degrees, and the natural consequence was that, for a long time, it yielded nothing but almost unlimited leisure. Now, that leisure was by no means wasted, for I employed it in considering the class of cases in which I was likely to be employed, and in working out theoretical examples; and seeing that crimes against the person have nearly always a strong medical interest, I gave them special attention. For instance, I planned a series of murders, selecting royal personages and great ministers as the victims, and on each murder I brought to bear all the special knowledge, skill and ingenuity at my command. I inquired minutely into the habits of my hypothetical victims; ascertained who were their associates, friends, enemies and servants; considered their diet, their residences, their modes of conveyance, the source of their clothing and, in fact, everything which it was necessary to know in order to achieve their deaths with certainty and with absolute safety to the murderer."
"How deeply gratified and flattered those great personages would have felt," I remarked, "if they had known how much attention they were receiving."
"Yes; I suppose it would have been somewhat startling, to the Prime Minister, for instance, to have learned that he was being watched and studied by an attentive observer and that the arrangements for his decease had been completed down to the minutest detail. But, of course, the application of the method to a particular case was the essential thing, for it brought into view all the incidental difficulties, in meeting which all the really interesting and instructive details were involved. Well, the particulars of these crimes I wrote out at length, in my private shorthand, in a journal which I kept for the purpose—and which, I need not say, I locked up securely in my safe when I was not using it. After completing each case, it was my custom to change sides and play the game over again from the opposite side of the board; that is to say, I added, as an appendix to each case, an analysis with a complete scheme for the detection of the crime. I have in my safe at the present moment six volumes of cases, fully indexed; and I can assure you that they are not only highly instructive reading, but are really valuable as works of reference."
"That I can readily believe," I replied, laughing heartily, nevertheless, at the grotesqueness of the whole proceeding, "though they might have proved rather incriminating documents if they had passed out of your possession."
"They would never have been read," rejoined Thorndyke. "My shorthand is, I think, quite undecipherable; it has been so made intentionally with a view to secrecy."
"And have any of your theoretical cases ever turned up in real life?"
"Several of them have, though very imperfectly planned and carried out as a rule. The poisoned cigar is one of them, though, of course I should never have adopted such a conspicuous device for presenting it; and the incident of the other night is a modification—for the worse—of another. In fact, most of the intricate and artistic crimes with which I have had to deal professionally have had their more complete and elaborate prototypes in my journals."
I was silent for some time, reflecting
