unravelling of "mysteries," except the identity of passers of
fraudulent paper and occasional murderers. The protection of
the banks is naturally the most important work that such an
agency can perform.

The National Bankers' Association has eleven thousand members.
"Pinkerton's Bank and Bankers' Protection" also has a large
organization of subscribers. These devote themselves to
identifying and running down all criminals whose activities
are dangerous to them. Here the agency and the police work
hand in hand, exchanging photographs of crooks and suspects
and keeping closely informed as to each other's doings. Yet
there is no official connection between any detective agency
and the police of any city. It is an almost universal rule
that a private detective shall not make an arrest. The
reasons for this are manifold. In the first place, the
private detective has neither the general authority nor the
facilities for the manual detention of a criminal. A blue
coat and brass buttons, to say nothing of a night stick, are
often invaluable stage properties in the last act of the
melodrama. And as the criminal authorities are eventually to
deal with the defendant anyway, it is just as well if they
come into the case as soon as may be. It goes without saying,
of course, that a detective per se has no more right to make
an arrest than any private citizen--nor has a policeman, for
that matter, save in exceptional cases. The officer is
valuable for his dignity, avoirdupois, "bracelets," and other
accessories. The police thus get the credit of many arrests
in difficult cases where all the work has been done by private
detectives, and it is good business for the latter to let them