Then as they move off and open out the engine to gain speed, Jock sweeps the horizon for a sight of enemy 'planes, for a strange curiosity grips him at the thought of Himmelman, and he wonders half aloud whether it will ever be his fate to meet this renowned airman, who was said to have brought down more machines than any other man living. But there is little time for soliloquy in the life of an airman in war time. He must ever be on the _qui vive_. And so for another half an hour, seeing no enemy 'planes to engage and remembering that he is out first of all for a reconnaissance, he watches the ground more and more closely. They have moved south some distance by this time, and have crossed the railway near Cléry. Below them they see the narrow waters of the Somme, glistening in the sunshine, for by now the sun is up, and there is the promise of a brilliant day. Jock is keenly watching the white road that leads from Peronne to Albert. "Ah! Ah!" He gasps. "What is that dark object that breaks the white, sunlit road, as though some dark shadow has fallen across it?" He points it out to the pilot, with a few gestures, and Dastral spirals round, and makes off towards the place at a rapid rate. As they approach the spot Jock scrutinises it yet more closely, for it looks suspicious. Then suddenly putting aside his glasses once more, he calls out, "Enemy column on the march!" "The deuce it is?" queries the pilot. "Yes, ammunition column, I think, but we'll soon find out." Then the tapping begins again, and the message is flung across the battle-ground and is picked up. With a swift mental calculation the observer has reckoned up when the head of the column will reach a certain point in the road, where a bridge carries the road over a tributary of the Somme. "Swis-s-s-h! Boom-m-m-m!" comes the first heavy fifteen-inch shell. It is a little short and another message on the keys is necessary. This time the shell falls plump right into the middle of the column, for so accurately are the guns trained, that, though they cannot see the object they are firing at, if the message sent only gives the exact position on the map, a direct hit is soon gained. The consternation of the Germans can be better imagined than described. Thinking themselves in comparative security so far behind the lines, a huge shell without the slightest warning explodes near by, and the next lands clean in the middle of the column. The object hit was a motor lorry conveying ammunition up to the guns. The first explosion is followed by another, more terrific than the first, for a couple of hundred shells are exploded, and when the smoke and dust have cleared away the observer and his pilot look down, and there is a huge gap in the column, for two of the lorries are blazing, several have been overturned, and one has disappeared entirely from view.