On their way up the coast there had been several occasions when, for a brief space of time, as a cloud was encountered, the onrushing fleet of seaplanes was swathed in a flurry of blinding snow. That was why Frank expressed the wish nothing of the kind might occur while the bombardment of the Belgian town on the edge of the Channel was in progress.

Zeebrugge is at the terminus of a canal, and had no sooner fallen into the hands of the Kaiser’s forces than they realized it would make an admirable place from which to start their submarine vessels against the shipping accustomed to using the English Channel.

The submarines were sent there in sections and assembled in shipyards arranged for that purpose. In fact, as the war progressed, Zeebrugge was rapidly becoming a very important center of military and naval industry.

As Frank well knew, Antwerp might have served the purposes of the Germans much better, but to reach the sea, vessels would have to cross a section of Holland, and the pugnacious little Dutch country had declared she would resist such invasion of her rights to the last man and vessel. As the Hollanders have always been good fighters, with an army of half a million men to back them, Germany had wisely chosen to make use of Zeebrugge.

Billy reported that the same excitement existed as at Ostend. Everywhere there were men seen running, and pointing upward toward the flock of aërial war craft.

“And I don’t blame them a bit for being scared,” he went on to say. “Two or three aëroplanes at a time are bad enough, but thirty in a bunch—holy smoke! it would frighten any American community half out of their wits, I’m thinking.”

“There goes the first shot at us!” announced Pudge, and it was strange how he, unconsciously perhaps, seemed to include the Sea Eagle in the list of invading aircraft, though they did not mean to lift a hand against the defenders of Zeebrugge.

“It fell far short,” observed Billy. “They’re so worked up they hardly know what they are doing. This time I reckon the seaplanes mean to keep above the reach of the shrapnel.”

“In which they show their good sense,” Pudge replied. “It only takes a little hit to bring an aëroplane down to the ground; and if a pilot and his helper ever dropped from this distance it means good-by.”

Except when one of the shrapnel shells broke below them, the air was clear enough for the boys to see everything that went on. Billy soon began to complain, as usual.

“Say, it’s ten times worse than a three-ringed circus,” he declared. “You can’t, with so many pilots dropping bombs while they circle around, possibly watch more than a small part of what’s happening down there.”

“Keep an eye on that mole along the edge of the water,” advised Frank. “That is where the submarines stay when they’re in port, and it’s being pounded pretty lively, you notice.”

“But why waste so much ammunition on an empty dock?” asked Billy.

“It’s of importance that they destroy it,” Frank explained. “I’ve got an idea they expect there may be several submerged boats alongside the mole. Perhaps, when the Germans had word from Ostend that the terrible air fleet was headed this way they guessed that the main object of the raid was to destroy their undersea boats; so they would be apt to sink them of their own accord, and in the natural way.”

They hovered over the spot, making short circles so they could witness all that occurred. M. Le Grande had produced binoculars from some part of his person, and was keeping them glued to his eyes constantly.

No doubt, in time to come, the boy aviators would often picture that wonderful scene in their minds when lying in their peaceful beds at home. With the buzzing of the flying seaplanes that darted to and fro, the sharp bursting of the shrapnel in furious volleys, and the heavier sound of the guns themselves far beneath, it certainly was an event never to be forgotten by those fortunate enough to be able to experience it at first hand.

Now one of them would call the attention of his comrades to some special feature of the battle scene that had caught his eye; and hardly would they rivet their gaze upon this before something else quite as thrilling called for notice.

They could even tell when the bombs, which the aviators were dropping, burst or failed in their intended mission. Long practice had made the airmen fairly accurate, though many of their missiles would be wasted, of course, and others go wide of the mark.

The sea wall was battered out of shape under the hurricane of bombs sent at it. Further on cars and motors were smashed when another well directed shot burst in their midst, causing a wild stampede on the part of a company of gray-coated Bavarians. These men had been firing several of the guns that could be elevated at an angle of almost fifty degrees, and were made especially with the idea of bringing down aircraft.

Several of the hostile airmen seemed to have marked out an oil tank as the target of their aim. It was a small thing to strike at such a distance, and a number of shots had gone wild. As though provoked at such a waste of precious ammunition, one of the most venturesome of the pilots suddenly swooped downward.

“Oh! watch him!” cried Pudge. “Now there’s going to be something doing worth seeing. I take off my hat to that chap for daring!”

He stopped talking then, for he had to actually hold his breath with admiration and fear while watching the evolutions of the bold voyager of the air.

The birdman swung this way and that with an eccentric movement that effectually balked the designs of the gunners to burst a shrapnel shell close to him. His altitude changed constantly, so they were unable to regulate the fuses of their shells to meet the conditions.

It looked as though he were simply defying them to do their worst, or begging a Taube of the enemy to risk rising to engage in a duel with him.

“Why, he’s right over their heads now, for you can hear all sorts of rifles going off in volleys,” said Billy. “Let’s hope he keeps out of their range.”

“Dories and dingbats, but doesn’t it beat anything you ever heard tell of?” Pudge was heard to say as he leaned over and watched the exciting picture; though he afterward declared it made him dizzy to see so many seaplanes speeding this way and that like angry bees when the hive is being robbed.

“Watch!” called Frank, who guessed from the signs that the bold pilot must by this time have reached a point where he was ready to have his assistant make the next cast.

Yes, they could see that he was leaning over now and apparently balancing some object in his hand. The seaplane grew somewhat steadier in its motion, as though they were willing to take additional chances in order to obtain stability.

“There it goes!” shouted Billy, after which they all stared, and listened to ascertain what the result of the cast would be.

There came an upheaval, accompanied by a billow of flame and dense black smoke that rose in a cloud. The aviator had succeeded at great peril to himself in dropping his bomb directly on the tank, with the result that a large quantity of precious gasoline or oil was lost to the enemy.

Even as high up as the Sea Eagle chanced to be at the time, those who were seated in the car could feel the wave of air concussion. The seaplane from which the fatal bomb had been dropped was seen to rock and plunge very much as a ship would in a gale at sea; but the navigator who controlled the levers knew his business, and managed to keep from turning turtle, a fate that all aviators view with unpleasant sensations.

Having accomplished his part of the raid, and earned the commendation of his superiors, the gallant airman began to climb the spiral staircase again, seeking a safer altitude. If all the others could do one-half as well as he had this raid would not soon be forgotten by the defenders of Zeebrugge.

“Not a single Taube have we seen since starting out!” said Pudge.

“Well, can you blame them for keeping under cover?” demanded Billy. “What could they do against thirty big seaplanes such as we’ve got with us? A rain of bombs would be the portion of any German pilot rash enough to put up a fight. He’d be courting sure death if he as much as showed his head.”

In the beginning of the war the Germans were far superior to either the British or the French with their aircraft. Their Taubes and Zeppelins caused much alarm in many a French and Belgian city as they flew over and dropped destructive bombs in the endeavor to terrorize the enemy.

That time, however, had gone by, and the assembling of this fleet of big British seaplanes was a plain notice to the Kaiser that the day of his supremacy of the air had passed into other hands, and that henceforth his aviators were to find themselves outclassed for daring and skill.

Around and around the hostile planes circled, each spitting out from time to time a fresh supply of deadly missiles that rained destruction on the military works below. Of course, it would presently come to an end. Then the wonderful fleet, having exhausted their supply of ammunition, would take up the return journey, leaving to the defenders of Zeebrugge the unpleasant task of counting up their great losses, and trying to conceal much of the truth, as all sides invariably do under similar conditions.

Frank was anticipating seeing some signal flying from the chief seaplane, a sort of “cease firing” order. It was just at this time that Billy discovered another exciting event being enacted, and called the attention of his companions to the fact.

“I’ve been watching that chap trying to hit that magazine for some time,” he called out. “He seems to be in hard luck, and now he’s going down like the other one did to tackle the thing at closer quarters. I only hope he gets through as well as the first one did.”

“Yes, there hasn’t been a single accident worth mentioning so far,” declared Pudge. “I’d hate to see him dropped like a stone. Rafts and rattlesnakes, but listen to the row they’re keeping up. They just seem to know what he’s trying to do. Look at them running away from that magazine like rats deserting a sinking ship.”

Swooping down, the Allies’ aviator was seen to head almost directly over the object of his particular attention. Calmly he measured the distance with his practiced eye, while the pilot slowed the seaplane down to a moderate speed.

They were in a perfect storm of bursting shrapnel, and at times the smoke fairly concealed the moving machine. Once Pudge gave a low cry of dismay, for he thought he had seen the seaplane plunging earthward a wreck, when there would be no question about the fate of its venturesome occupants.

Then he took fresh heart as a puff of air blew the white and gray smoke aside, and it was discovered that the aëroplane was still afloat.

“Oh! why doesn’t he do it?” cried Pudge. “It seems as if my heart would climb up in my throat, I’m that worried. Throw now! There, he’s going to do it, boys, don’t you see? I wonder if that shot will be any better——”

Pudge did not finish his sentence, for just then there was a frightful roaring sound. The magazine was seen to fly to a million pieces, while up rose a vast cloud of smoke. The atmosphere was made to fairly quake under the tremendous concussion, so that Pudge clutched hold of Billy, who was alongside, as though he actually feared they would be overturned and hurled into space.

Frank’s heart also seemed to stand still, but it was not on account of any fear for himself. When through the rising billow of black smoke he saw that the daring author of this last blow at the invader’s army was apparently uninjured, Frank breathed freely again.