And, certainly, behind the light blue eyes that could look with such apparent ingenuousness out of his plump, bland face there was the subtle mind of a psychologist. Barnstable, true to his attitude of the plain business man, would have been the first to ridicule the idea publicly if anyone had dubbed him "the psychological detective." That, to his mind, would have savored of charlatanism. He would have said: "I am nothing so strange and mystifying as that--I am a plain business man." But in reality there was no new discovery of the investigating psychologists of which he did not avail himself at once. His ability to clothe himself with the thoughts of the criminal as an actor clothes himself with a role, was marvelous; he knew the criminal soul. That is to say, he knew the human soul. He refused to see anything extraordinary in this. "It is only my business to know such things," he would say. "We know many things. It is our business to know them. There is no miracle about it." This was the public character he had created for himself, and emphasized--that of the plain business man. This was his mask. He was so subtle that he hid the vast range of his powers behind an appearance of commonplaceness. Wilton Barnstable never disguised himself, in the ordinary sense of the term. That is, he never resorted to false whiskers or wigs or obvious tricks of that sort. But if Wilton Barnstable were to walk into a convention of blacksmiths, let us say, he would quite escape attention. For before he had been ten minutes in that gathering he would become, to all appearances, the typical blacksmith. If he were to enter a gathering of bankers, or barbers, or bakers, or organ grinders, or stockbrokers, or school-teachers, a similar thing would happen. He could make himself the composite photograph of all the individuals of any group. He disguised himself from the inside out. This art of becoming inconspicuous was one of his greatest assets as a detective. Newspaper and magazine writers would have liked to dwell upon it. But he requested them not to emphasize it. As he modestly narrated his triumphs to the young journalists, who hung breathless upon his words, he was careful not to stress his talent for becoming just like anybody and everybody else--his peculiar genius for being the average man.