Aviators of the Allies, too, were busy. One of their aerial squadrons proceeded along the coast on March 16 and attacked the military posts at Ostend and Knocke. These aviators had as one of their main objective points the German coast batteries at the latter place. But the squadron was seen from a German observation balloon at Zeebrugge, and a flock of "Taubes" made a dash for their enemy's craft. The Germans were not as skillful airmen, however, and they found it necessary to retire. Five British aviators made an attack on the German submarine base at Hoboken, southwest of Antwerp, and destroyed a submarine and wrecked two others. This raid was made without injury to the aviators, the only accident being the necessity of one of the aircraft to descend, which it did, only to find it had landed on Dutch territory and must be interned. The excellence of the Allies' flying was not confined to the English. Belgian and French airmen, as well as British, flew almost constantly over Ostend, Zeebrugge, Roulers, Aubers, and such other places as German soldiers and their supplies were in evidence. The Belgian airmen dropped bombs on the aviation field at Ghistelles on March 27, and on the following day a Zeppelin hangar was destroyed at Berchem-Sainte-Agathe, near Brussels. On March 30, 1915, ten British and some French aviators flew along the coast from Nieuport to Zeebrugge and dropped bombs on magazines and submarine bases. The last day of the month saw the destruction of the German captive balloon at Zeebrugge and the death of its two observers. The Belgian aviators on the same day threw bombs on the aviation field at Handzaeme and the railroad junction at Cortemarck, and, south of Dixmude, the famous birdman, Garros, fought a successful duel in the air with a German aviator. An aviator of the Allies flew over the aerodrome at Lille on April 1, 1915, and dropped a football. The Germans hastened to cover. When the ball bounced prodigiously as a result of being dropped from such a height, the Teutons thought it was some new kind of death dealer, and remained in their places of safety. In fact, they remained there quite a few minutes after the football had ceased to bounce. When they finally emerged most cautiously and approached the object of their terror, they read this inscription on it: "April Fool--Gott strafe England."