"That road's blocked," he said firmly, "and she's goin' to stay blocked." And he got his men to rig a sort of banner of fabric attached to a long iron picket-pin harpoon arrangement, painted a sentence in German on it, and took it up with him. They found the road still blocked, but columns of troops tramping in streams over the fields to either side. They spent a full hour scattering these and chasing them all over the landscape, had to break off the game to take on another fight with a crowd of Hun scouts, were joined by a stray Flight or two who saw the fight and barged into it, and after a mixed fast and furious "dog-fight" at heights running from anything under 300 feet to about as many inches, chased the Hun machines off. They came back in triumph down the deserted road and the empty fields, spattering the last of their rounds into the wrecked lorries and wagons still lying there, and then, as they passed over the piled wreckage at the crater, Dennis leaned out and dropped his streamered harpoon overboard. It plunged straight, hit, and stuck neatly upright displaying its legend clearly to anyone on the ground. "What was on it?" said Dennis in answer to the questions of the Flight later on. "It was a notice in German. Maybe it was bad German, but it was a dash good notice. It said 'No Thoroughfare,' and I fancy we've taught the Huns what it means anyhow." They, and a good many of their fellow squadrons, had, on this and on other road and rail Lines of Communication. They lost men and they lost machines; but the expected fresh attack on the line did not develop at dusk as foretold. And that night the weary troops slept a solid life-renewing six hours. XVI THRILLS It was a bad day for kite-balloon work; first, because the air was not clear and the visibility was bad, and second, because there was an uncomfortable wind blowing, and the balloon was jerking and swaying and lurching at the end of its long tether, making it hard for the observers to keep a steady eye on such targets as they could pick up, and still harder to plot out angles and ranges on the map spread on the table sticking out from the side of the basket. But hard fighting was going on, and the line was getting badly hammered, so that every balloon which could get up was in the air, and every observer was hunting for hostile battery positions, directing the fire of our guns on to them, and doing all they could to lessen the shell-fire that was pouring down on our infantry in their scanty trenches. At times a swirl of mist or cloud came down and shut off the view altogether from the balloons; but they hung on, and stayed aloft waiting for a clear and the chance to observe a few more rounds the moment they got it.