"Yes, by Jove, there must be a whole division of them. Here goes!" And dropping the glasses into the pocket prepared for them, he rapidly uncoils the long pendant wire, and begins to tap the keys of his instrument. "Caught them on the nap, Jock, eh? Stroke of luck. Case of the early bird. Tell the heavies to give 'em hell, old man," shouted Dastral, but the conversation was carried away into the morning breeze, for jock was already sending the message which would shortly bring the thunder. "Zip-zip-zip, zur-r-r-r, zip!" went the brief coded message, back over Longueval and Ginchy; over Contalmaison and the trenches to where the British heavy batteries were waiting. Behind the Ancre, in a little dug-out, an expert operator catches up the message. He has been waiting for it impatiently since dawn. The brief tapping which his receiver picks up, tells him exactly the spot on the terrain behind the enemy's lines where the thunder is needed. The whole map is scaled out into tiny sections and sub-sections, each with a number or letter to indicate the point where the concentrated fire is needed. "Quick!" cries the operator to the little exchange. "Give me H.Q. Heavy Batteries." Then as the reply comes through he gives: "A-2-3. Concentrated fire!" Within four minutes, while the hornet still circles over the luckless Germans, now alive to their danger and rushing over each other in their haste to finish the detrainment of the column, flashes of fire are seen away to the west, and through the air comes a heavy explosive shell. It is followed by another and yet another. As they explode, the observer sees the earth blotted out from view for a few seconds. He notes how near the first shots fall to the target. Then he taps his keys once more. "Zur, zip-zip!" cries the machine, and the next shell falls into the midst of the column, destroying nearly a whole train. And so for another ten minutes the airmen remain, altering the range until at least a dozen direct hits are scored, and the damage done to the railway, the trains, and the division or so of men is tremendous. Very quickly, however, the men are scattered and placed out of danger, hiding in the woods, and under hedges and trees where they cannot be seen. The Germans, aware of that dangerous pest overhead, have rushed up anti-aircraft guns to deal with it, and have also telephoned to the nearest aerodromes for their beloved Fokkers. So shortly after, having done as much damage as possible in a short space of time, the hornet moves off to reconnoitre further afield. "Watch for their verdomt Fokkers, Jock," cries the pilot. "They may appear at any minute. Himmelman himself may be in the neighbourhood." "Himmelman?" queries Jock, more to himself than to his comrade, as he looks round uneasily, for on the previous day he had heard some tall tales of the doings of this crack German flyer.