“When we want a detective to take the part of a plumber _we get a plumber_, and when we need one to act as a boiler-maker we go out and get a _real one_—if we haven’t one on our pay-rolls.” “But,” I replied, “when you need a man to go into a private family and pretend to be an English clergyman, or a French viscount, or a brilliant man of the world—who do you send?” The “head” smiled. “The case hasn’t arisen yet,” said he. “When it does I guess we’ll get the real thing.” The national detective agency, with its thousands of employees who have, most of them, grown up and received their training in its service, is a powerful organization, highly centralized, and having an immense sinking fund of special knowledge and past experience. This is the product of decades of patient labor and minute record. The agency which offers you the services of a Sherlock Holmes is a fraud, but you can accept as genuine a proposition to run down any man whose picture you may be able to identify in the gallery. The day of the impersonator is over. The detective of this generation is a hard-headed business man with a stout pair of legs. This accumulated fund of information is the heritage of an honest and long established industry. It is seventy-five per cent of its capital. It is entirely beyond the reach of the mushroom agency, which in consequence has to accept less desirable retainers involving no such requirements, or go to the wall. The collection of photographs is almost priceless and the clippings, letters, and memoranda in the filing cases only secondarily so. Very few of the “operators” pretend to anything but common-sense with, perhaps, some special knowledge of the men they are after. They are not clairvoyants or mystery men, but they will tirelessly follow a crook until they get him. They are the regular troops who take their orders without question. The real “detective” is the “boss” who directs them.