wire. The sapper is the "handy man" of the Army.

The location of these Headquarters on our side of the line is a constant
object of solicitude to the enemy on the other. Very few officers even
on our side know where they all are. I had confided to me, for the
purpose of my official duties, a complete list of such Headquarters,
and the first thing I did, in pursuance of my instructions, was to
commit it to memory and then burn it. To find out the enemy's H.Q.--with
a view to making them as unhealthy as possible--is almost entirely the
work of aeroplane reconnaissance. To discover the number and composition
of the units whose H.Q. they are is the work of our "Intelligence." Of
our Intelligence work the less said the better--by which I intend no
aspersion but quite the contrary. The work is extraordinarily effective,
but half its effectiveness lies in its secrecy. It is all done by an
elaborate process of induction. I should hesitate to say that the "I"
officers discover the location of the H.Q. of captured Germans by a
geological analysis of the mud on the soles of their boots, in the
classical manner of Sherlock Holmes; but I should be equally indisposed
to deny it. There is nothing too trivial or insignificant to engage the
detective faculties of an "I" man. He has to allow a wide margin for the
probability of error in his calculations; shoulder-straps, for example,
are no longer conclusive data as to the composition of the enemy's
units, for the intelligent Hun has taken of late to forging
shoulder-straps with the same facility as he forges diplomatic
documents. Oral examination of prisoners has to be used with caution.
But there are other resources of which I shall say nothing. It is not
too much to say, however, that we have now a pretty complete
comprehension of the strength, composition, and location of most German
brigades on the Western front. Possibly the Germans have of ours. One
thing is certain. Any one who has seen the way in which an Intelligence
staff builds up its data will not be inclined to criticise our military
authorities for what may seem to an untutored mind a mere affectation of
mystery about small things. In war it is never safe to say _De minimis
non curatur_.

If "I" stands for the Criminal Investigation Department (and the study
of the Hun may be legitimately regarded as a department of criminology)
the Provost-Marshal and his staff may be described as a kind of
Metropolitan Police. The P.M