be wrong. For six years--from 1895 to 1901--this system
was in force at Scotland Yard. The maximum number of identifications in
any one year was 500. In 1913, by the aid of finger-prints, 10,607
persons were identified.

Roughly, it is all a matter of classification into "arches," "loops,"
"whorls," and "composites." It is intricate to describe, but simple to
carry out. To the uninitiated it inevitably suggests the old problem
"think of a number, double it--."

What happens is this: Every print for primary classification purposes is
considered as a loop or a whorl. The fingers are taken in pairs and put
down something like this:

L. L. W. L. L.
--------------------
L. W. W. W. W.

Now a whorl occurring in the first pair would count sixteen, in the
second, eight, and so on. The loops are ignored. Consequently, the
number in the above formula is:

0. 0. 4. 0. 0.
----------------
0. 8. 4. 2. 1.

These are added together and become 4-15. The figure 1 is added above
and below, and the searcher knows that he has to look for the record he
wants in the sixteenth file of Number 5 horizontal row in a cabinet
specially arranged.

Of course, sub-classification is carried much farther than this, but it
is scarcely necessary to elaborate the point.

Day by day, the prison governors from all parts of the country are
sending in records to be added to the files, and police authorities,
also from all parts of the country, are asking for prisoners to be
identified.

An interesting story concerns two men whom we will call Robinson and
Jones, who were tried for different offences the same day. Robinson was
rich; Jones was not. Robinson received a long sentence, Jones a light
one.

Probably they arranged it all in the prison van, but anyhow, when they
reached the gaol they had changed identities--and sentences. All went
well until a short time before the _soi-disant_ Jones was due to be
released. Then his finger-prints were taken, compared with those of
Jones in the files, and found not to correspond.

Half an hour later wires were being exchanged between Scotland Yard and
the prison, and, to the mutual consternation of the two men, the little
scheme was revealed. Finger-prints had outwitted them.

Save for a few filing cabinets stretching from floor to ceiling in a
well-lighted room, there is little apparent difference between the
Finger-print Department at Scotland Yard