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.