"The poor devils!" added the pilot, altering his controls slightly, and wheeling round to the south to pick up the enemy's lines more clearly at a point where they made a sharp curve. They could now clearly see both the British and the German trenches. Three long, scarred and ragged lines of brown earth showed clearly where the enemy's front-line, reserve and support trenches stood. Long, twisting lines of similar demarcation showed where the communication trenches ran. Now they were over No Man's land, sailing along serenely, and the artillery down below had already opened the morning concert on both fronts, when-- "Biff, puff----!" came a time-fuse shrapnel and burst scarcely a hundred feet in front of the machine. Then another and another as the "Archies" below spotted the hornet, and tried to give her a packet. Suddenly they were in a cloud of yellow smoke and half-poisonous fumes, which made them gasp and sputter. Then, owing to the bursting of the shells and the heavy concussions they found themselves in a succession of air-pockets. "Look out, Jock!" cried Dastral, as the machine rocked and swayed, banking over once or twice as though she had been hit. For several minutes they ran the gauntlet of this heavy fire from the German A.A. guns, but the terrific speed at which they were travelling--now nearly one hundred and twenty miles per hour--soon carried them beyond the range of the enemy's guns. Then it was that the day's work really began. Their orders were to reconnoitre behind the enemy's lines and to report by wireless code any occurrence, such as the threat of a massed attack by infantry, the moving of transport columns, or the locating of heavy artillery. It was also necessary, above all, to watch the skies for the appearance of hostile aircraft. The other 'planes which started with the hornet that morning are seen low down on the horizon, to the north and the south. They also are searching all the terrain for any signs of activity on the part of the Boche. Spurts of flame, like jets of fire, are seen in many places. These are the German fieldguns firing upon the British trenches. The observer does not make any particular note of these; he is out for bigger game. Suddenly, the observer steadies his glasses, resting his arm for a moment on the side of the fuselage. The loop line of the Combles-Ginchy railway is just ahead of them and slightly on their right. Though it is very early yet, Jock notices that the line about Ginchy is crowded with traffic. "Ahoy there, Dastral!" he calls down the speaking tube. "Yes," comes back the laconic answer. "Railway line blocked with traffic. Troops detraining, I think. Put her over a bit." "Right-o!" Dastral jams over the rudder bar with his foot and, responding to her huge tail rudder the hornet comes round in a swift circle, banking a little as the joy-stick is also put over. Then Jock takes another view, exclaiming, as he does so,