After several hours of intense concentration the aviators approach their target, and although they have charted the course constantly they now spend some time in flying back and forth while they check off on a large-scale map the landmarks about the target and satisfy themselves that their long flight will not be valueless if the bombs are dropped with accuracy. In the meantime the sound of the motors, together with the telegraphed intelligence from other Hun towns, tells the enemy that Allied night bombers are in the vicinity. The Huns in charge of the anti-aircraft defences stationed about the target direct huge beams of numerous searchlights toward the sky and an intense barrage is put up above and around the target by the Hun batteries. The air is filled with shrapnel from bursting shells at the altitude at which the machine is flying, for the Huns have accurate instruments which gauge the altitude of an aeroplane from the sound vibrations of its engines. The aviators, however, are still intent on picking out their target (probably a factory which manufactures war material) and have not yet entered the barrage. The Huns, I imagine, often wondered why British bombers flew about a town for such a long time before bombing; the inhabitants always had more than enough time to enter the dug-outs before the bombs dropped. The British bombers, however, were not making war on women and children; they were intent on destroying a poisonous gas factory or other targets of military importance; so they flew about the town until the target was accurately located; then and not till then, they throttled down their engines and glided swiftly down between the searchlight beams and below the barrage of bursting shells, for once the engines are throttled down the enemy's sound instruments are valueless and the anti-aircraft barrage ranged at the previous altitude of the aeroplane fills the air with shrapnel far above the rapidly descending plane. A quick adjustment of bomb-sights to compensate for the altitude, speed, and drift of the plane and the front fore-sight soon is in line with the target, and after a pause the back fore-sight coming in line with the back-sight gives, with the previously adjusted stop-watch, the exact moment for releasing the first bombs. The plane passes over the target and turns on a steep "bank," while the aviators watch for the burst of the bombs. The bomb-sight is readjusted to the reduced altitude, another sight taken, the remainder of the bombs released, and then, nose down, engine "full out," the huge plane rushes through the lowered barrage for more congenial surroundings.