For the greater part of the winter months the “Front” was, to all appearances above ground, as deserted as the Sahara and almost as silent.  Everybody who had to be there was, for obvious reasons, invisible, and the misguided wayfarer who found himself between the lines was in a wilderness whose intimidating silence was occasionally interrupted by the sound of projectiles coming he knew not whence and going he knew not whither.  The effect was inexpressibly depressing.  But a mile or two behind our lines all was animation, for here were Battalion and Brigade Headquarters, all linked up by a network of field telephones, which in turn communicated with Divisional Headquarters farther back.  Baskets of carrier-pigeons under the care of a pigeon fancier, who figures in the Army List as a captain in the R.E., are kept at these places for use in sudden emergency when the wires get destroyed by shell-fire.  The sappers must, I think, belong to the order of Arachnidae; they appear to be able to spin telephone wires out of their entrails at the shortest notice.  Moreover, they possess an uncanny adhesiveness, and a Signal Company man will leg up a tree with a coil of wire on his arm and hang glutinously, suspended by his finger-tips, while he enjoys the view.  These acrobatic performances are sometimes exchanged for equestrian feats.  He has been known to lay cable for two miles across country at a gallop with the cable-drum paying out lengths of 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