The licensed detective who sends out a hurry call for assistants is apt to be able to get only men whom he would otherwise not employ.

In this chapter, the word "national," as applied to a detective agency, refers not to the title under which such an agency may do its business, but to the fact that it is organized and equipped to render services all over the country.
In this connection it is worth noticing that the best detective agencies train their own operators, selecting them from picked material.

The candidate must as rule be between twenty and thirty-five years of age, sound of body, and reasonably intelligent.

He gets pretty good wages from the start.

From the comparatively easy work of watching or "locating," he is advanced through the more difficult varieties of "shadowing" and "trailing," until eventually he may develop into a first-class man who will be set to unravel a murder mystery or to "rope" a professional criminal.