I looked up and saw a narrow biplane, apparently a Roland, rushing towards our bus. My pilot turned vertically and then side-slipped to disconcert the Boche's aim. The black-crossed craft swept over at a distance of less than a hundred yards. I raised my gun-mounting, sighted, and pressed the trigger. Three shots rattled off--and my Lewis gun ceased fire. Intensely annoyed at being cheated out of such a splendid target, I applied immediate action, pulled back the cocking-handle and pressed the trigger again. Nothing happened. After one more immediate action test, I examined the gun and found that an incoming cartridge and an empty case were jammed together in the breech. To remedy the stoppage, I had to remove spade-grip and body cover. As I did this, I heard an ominous _ta-ta-ta-ta-ta_ from the returning German scout. My pilot cart-wheeled round and made for the Hun, his gun spitting continuously through the propeller. The two machines raced at each other until less than fifty yards separated them. Then the Boche swayed, turned aside, and put his nose down. We dropped after him, with our front machine-gun still speaking. The Roland's glide merged into a dive, and we imitated him. Suddenly a streak of flame came from his petrol tank, and the next second he was rushing earthwards, with two streamers of smoke trailing behind. I was unable to see the end of this vertical dive, for two more single-seaters were upon us. They plugged away while I remedied the stoppage, and several bullets ventilated the fuselage quite close to my cockpit. When my gun was itself again, I changed the drum of ammunition, and hastened to fire at the nearest Hun. He was evidently unprepared, for he turned and moved across our tail. As he did so, I raked his bus from stem to stern. I looked at him hopefully, for the range was very short, and I expected to see him drop towards the ground at several miles a minute. He sailed on serenely. This is an annoying habit of enemy machines when one is sure that, by the rules of the game, they ought to be destroyed. The machine in question was probably hit, however, for it did not return, and I saw it begin a glide as though the pilot meant to land. We switched our attention to the remaining Hun, but this one was not anxious to fight alone. He dived a few hundred feet, with tail well up, looking for all the world like a trout when it drops back into water. Afterwards he flattened out and went east. During the fight we had become separated from the remainder of our party. I searched all round the compass, but could find neither friend nor foe. We returned to the aerodrome where hostile craft were first sighted. There was no sign of C.'s machine or of the others who dived on the first group of Huns. Several German machines were at rest in the aerodrome.