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. and his A.P.M.’s are the Censores Morum of the occupied towns, just as the Camp Commandants are the Aediles.  It is the duty of an A.P.M. to round up stragglers, visit estaminets, keep a cold eye on brothels, look after prisoners, execute the sentences of courts-martial, and control street traffic.  Which means that he is more feared than loved.  He is never obtrusive but he is always there.  I remarked once when lunching with a certain A.P.M. that although I had already been three weeks at G.H.Q., and had driven through his particular district daily, I had never once been stopped or questioned by his police.  “No,” he said quietly, “they reported you the first day two minutes after you arrived in your car, and asked for instructions; we telephoned to G.H.Q. and found you were attached to the A.G.’s staff, and they received orders accordingly.  Otherwise you might have had quite a lively time at X——­,” which was the next stage of my journey.  G.H.Q. itself is patrolled by a number of Scotland Yard men, remarkable for their self-effacing habits and their modest preference for dark doorways.  Indeed it is easier for a camel to go through the eye of a needle than to get into that town—­or out of it.  As for the “Society ladies,” of whom one hears so much, I never saw one of them.  If they were there they must have been remarkably disguised, and none of us knew anything of them.  A conversational lesson in French or English may be had gratuitously by any Englishman or Frenchman who tries to get into G.H.Q.; as he approaches the town he will find a French sentry on the left and an English sentry on the right, the one with a bayonet like a needle, the other with a bayonet like a table-knife, and each of them takes an immense personal interest in you and is most anxious to assist you in perfecting your idiom.  They are students of phonetics, too, in their way, and study your gutturals with almost pedantic affection for traces of Teutonisms.  If the sentry thinks you are not getting on with your education he takes you aside like Joab, and smites you under the fifth rib—­at least I suppose he does.  If he is satisfied he brings his right hand smartly across the butt of his rifle, and by that masonic sign you know that you will do.  But it is a mistake to continue the conversation.