"I am not in the least degree either a sharp or an observant man myself. I try to get inside the skin of a sharp man and see how things would strike him. I remember going to the Scotland Yard museum, and looking at the letter which was received from the police and which purported to come from the Ripper. Of course it may have been a hoax, but there were reasons to think it genuine, and in any case it was as well to find out who wrote it. It was written in red ink in a clerkly hand. I tried to think how Holmes might have deduced the writer of that letter. The most obvious point was that the letter was written by some one who had been in America. It began, "Dear Boss," and contained the phrase, "Fix it up," and several others which are not usual with Britishers. Then we have the quality of the paper and handwriting, which indicate that the letters were not written by a toiler. It was good paper and a round, easy, clerkly hand. He was therefore a man accustomed to the use of a pen.
Having determined that much we cannot avoid the inference that there must be somewhere letters which this man had written over his own name, or documents or accounts that could be readily traced to him. Oddly enough the police did not, as far as I know, think of that, and so they failed to accomplish anything. Holmes' plan would have been to reproduce the letters in facsimile and on each plate indicate briefly the peculiarities of the handwriting. Then publish these facsimiles in the leading newspapers of Great Britain and America, and in connection with them offer a reward to anyone who could show a letter or any specimen of the same handwriting. Such a course would have enlisted millions of people as detectives in the case."