I have already told you that our main work in umpty squadron is long reconnaissance for G.H.Q. and offensive patrol. Special photographic stunts such as happened to-day are rare, thank the Lord. But our cameras often prepare the way for a bombing expedition. An observer returns from a reconnaissance flight with snapshots of a railhead, a busy factory, or an army headquarters. Prints are sent to the "I" people, who, at their leisure, map out in detail the point of interest. No fear of doubtful reports from the glossed surface of geometrical reproduction, for the camera, our most trusted spy, cannot distort the truth. Next a complete plan of the chosen objective, with its surroundings, is given to a bombing squadron; and finally, the pilots concerned, well primed with knowledge of exactly where to align their bomb-sights, fly off to destroy. For the corps and army squadrons of the R.F.C. photography has a prominent place in the daily round. To them falls the duty of providing survey-maps of the complete system of enemy defences. Their all-seeing lenses penetrate through camouflage to new trenches and emplacements, while exposing fake fortifications. The broken or unbroken German line is fully revealed, even to such details as the barbed wire in front and the approaches in rear. For clues to battery positions and the like, the gun country behind the frontier of the trenches is likewise searched by camera. One day a certain square on the artillery map seems lifeless. The following afternoon an overhead snapshot reveals a new clump of trees or a curious mark not to be found on earlier photographs. On the third day the mark has disappeared, or the trees are clustered in a slightly different shape. But meanwhile an exact position has been pin-pointed, so that certain heavy guns busy themselves with concentrated fire. By the fourth day the new gun-pits, or whatever it was that the Hun tried to smuggle into place unnoticed, have been demolished and is replaced by a wide rash of shell-holes. Wonderful indeed is the record of war as preserved by prints in the archives of our photographic section. For example, we were shown last week a pair of striking snapshots taken above Martinpuich, before and after bombardment. The Before one pictured a neat little village in compact perspective of squares, rectangles, and triangles. The Aftermath pictured a tangled heap of sprawling chaos, as little like a village as is the usual popular novel like literature.