deliberation that a young student might apply to the pursuit of an exact
science. He took a room in Jermyn Street, and began his studies in every
moment he could spare off duty. "I haunted night clubs; I went to
gambling houses; I was a frequenter of any resort where one was likely
to meet rogues or tricksters. I stored my memory with faces, and made
myself friendly with all sorts of people--waiters, barmen, and
hall-porters. So it was that I got hints that I should never have got by
any other method, and scores of times, years afterwards, I received
information from the channels I had formed when I began. To show the
value of some of these acquaintances I may tell you that when some idea
of my identity leaked out at one of these clubs an American crook--he
was drunk--declared openly that he would shoot me at sight. The waiter
contrived to draw the cartridges from his revolver, and to give me a
hint as I entered. And sure enough my man stood up, took aim, and pulled
the trigger of the empty weapon. I hit him on the jaw, and let it rest
at that. But if I hadn't treated that waiter right, I might have been a
dead man now."

The personal factor is an important one in dealing with informants.
There is not very often ill-feeling between criminals and detectives. A
slight straining of red-tape will sometimes have wide-reaching results.
A detective, conveying a prisoner from Liverpool to London, offered the
latter a cigar. "You're a good sort," exclaimed the man impulsively.
"Tell you what; I'm in for it, I know. But I can do you a bit of good.
It was X. and Z. who did that Hatton Garden business." And so was
provided a clue to an apparently insoluble mystery.

At the end of three months, the probationer, if he has qualified, finds
himself a fully-fledged "detective-patrol." Thereafter he has to pass an
examination whenever he is promoted, and may pass upwards through the
grades of third, second, and first class detective-sergeants to second,
first, and divisional inspector, and even eventually to chief
detective-inspector.

The everyday duties of the C.I.D. are legion. There are "Informations"
passing between headquarters and the different stations daily, almost
hourly. Stolen property has to be traced, pawnbrokers visited, convicts
on licence watched, reports made, inquiries conducted by request of
provincial police forces. It means hard, painstaking work from morning
to night.

As I have said, so far as is consistent