The Adventure of the Engineer's Thumb

Of all the problems which have been submitted to my friend, Mr. Sherlock Holmes, for solution during the years of our intimacy, there were only two which I was the means of introducing to his notice—that of Mr. Hatherley’s thumb, and that of Colonel Warburton’s madness. Of these the latter may have afforded a finer field for an acute and original observer, but the other was so strange in its inception and so dramatic in its details that it may...