promotion in the detective service, in addition to educational
examinations carried out independently by the Civil Service
Commissioners. Here is a question put at an examination for promotion to
detective-sergeant which might form the skeleton of a detective story.

"A night-watchman, in going his rounds, discovers two men attempting to
break open a safe on the premises. Both men make good their escape by a
window, but one of them receives a blow on the head from the watchman
which causes blood to flow, while the other leaves his jacket behind.

"The watchman can give a fair description of the men. In the jacket left
behind, which bears no maker's name, are found the following:--(1) A
return-half ticket to Birmingham from London; (2) A snapshot of a lady
having the appearance of a music hall performer, signed 'Kitty,' but
with no photographer's name; (3) a letter (no envelope) as follows:--

"King Street.

'DEAR TOM.--I hope you are coming up on Tuesday. Things are bad
here since Bill got his three months.
'MARY.'

"State as fully as you can what steps you suggest should be taken to
trace the offenders. How could the articles found be made use of in the
enquiry?"

The preliminary examination is only the first step. The young man who
passes finds himself a "patrol on probation," with the knowledge that if
he does not justify himself he will be returned to the blue-coated
ranks. He is put to school again--the little-known detective school that
is maintained at Scotland Yard, with Detective-Inspector Belcher at its
head. There are lectures on law, and even lantern lectures. He is taught
the methods of criminals, from gambling sharps to forgers, from
pickpockets to petty sneak-thieves. The Black Museum primarily exists
for his instruction. He is shown jemmies, coining implements,
shop-lifting devices, and the latest word in the march of scientific
burglary--the oxy-acetylene apparatus. All that ingenuity and experience
can suggest for the confusion of the criminal is taught him. He is shown
where an expert must be called in, and where his own common-sense must
aid him. He is taught something of locks, something of finger-prints,
something of cipher-reading. He learns the significance of trivialities,
and the high importance of method.

I have said that the detective must know when to call in the expert.
Science plays no inconspicuous part in many investigations, and there is
a little corps