of consulting specialists whose aid is always available.
It was the work of the analyst that proved the guilt of men like Seddon
and Crippen. The microscopist has brought more than one forger to
justice. A murder was proved because a tool-maker's aid was enlisted to
decipher some scratches on a chisel. A blackmailer was captured because
a paper manufacturer identified a peculiar make of paper on which a
letter was written. And, of course, the help of the medical jurisprudent
is a commonplace of criminal investigation.

The finger-print experts are on the staff; so, too, are the
photographers. There is a big magic lantern used in connection with the
latter department which has made clear more than one mystery by the
enlargement of some photograph. In one case an envelope with a blurred
post-mark was picked up on the scene of a robbery. It was enlarged, and
so the name of a town was picked out. In an hour or two the criminal was
under arrest.

CHAPTER VI.

MORE ABOUT INVESTIGATION.

Outside fiction, the real detective does not disguise himself in any
elaborate or melodramatic fashion. He will not wear a false moustache or
a wig, for instance. But the beginner is taught how a difference in
dressing the hair, the combing out or waxing of a moustache, the
substitution of a muffler for a collar, a cap for a bowler will alter
his appearance. They keep a "make-up" room at headquarters, its most
conspicuous feature being a photograph of a group of dirty-looking
ruffians--detectives in disguise. But it is a disguise the more
impenetrable because there is nothing that can go wrong with it. Yet not
half a dozen times in a year is the make-up room used.

The kind of case in which a disguise is useful may be illustrated. Some
thieves had broken into St. George's Cathedral, at Southwark, and then
rifled the Bishop's Palace. The booty they secured was worth some three
thousand pounds, and they left not the faintest trace behind. The
officer charged with the investigation resolved on a long shot. He
dressed himself--I quote a newspaper report--"in a long overcoat and
slouched hat, sported a heavy chain, smoked a big cigar, and was well
supplied with gold." In this attire he made himself conspicuous about
Vauxhall. Among the "crooks" of that neighbourhood, it soon became known
that a Jew receiver--one Cohen, of Brick Lane, Whitechapel--was about,
and in a very short while the "receiver" knew all that he needed to
arrest th