“Zip! we’re off!” cried Billy, as he heard the familiar whir of the motors, and felt the forward push of the sea and air craft.

Pudge was not so accustomed to being aboard one of the Sea Eagles when starting out on a cruise. His father, knowing the customary clumsiness of Pudge, had preferred as a rule that the fat boy stay upon the solid ground while his more agile chums attempted the aërial stunts.

But Pudge complained so much that Frank had thought it best to let him accompany them on this wonderful journey. It was likely to eclipse anything they had ever experienced before, and must ever remain as a memory worth while.

The speed increasing, they were soon rushing over the surface of the harbor at a furious rate. Then, as Frank slanted the ascending rudder, they left the water to course upward at a low angle, which, however, could be increased as they circled the harbor.

Loud cheers came to their ears from the shore, where that crowd had been standing. They were echoed, too, from several other points, showing that all Dunkirk must be on the alert this morning, as though it might be in the air that wonderful things were about to transpire.

“Are those cheers for us, do you think, Frank, or because they’ve discovered the fleet coming along?” Billy asked, although he had already waved his hand toward the shore.

“It’s hard to tell,” Frank replied. “Though they must have glimpsed the bunch heading this way, and guessed what it all means. I don’t see any person running to hide in a cellar, as they do when the Taubes are around.”

Mounting higher, they waited for the arrival of the fleet. It was a sight never before witnessed. The air was fairly filled with buzzing seaplanes of various patterns, jockeying for position much as is seen on the race course before the signal to start is given by the firing of a pistol.

“Listen to all the racket, will you?” cried Pudge, and indeed the noise of so many motors and whirling propellers did sound strangely.

“It’s like a young Niagara, that’s what I’d call it!” declared Billy. “Why, sometimes you can’t hear yourself think for the Bedlam that’s broken loose. Say, tell me what the Germans up the coast will think has struck them when this flock descends on Zeebrugge, and batters away at the docks and the submarine bases.”

“They’re all under the charge of a central seaplane, too,” added Frank. “For, if you notice, the signals are always sent from that one just passing us now.”

One of the muffled figures in the other aircraft waved a hand at them. Something was said at the same time, which Frank took for granted must be a question as to whether they expected to accompany the raiders.

He nodded his head in the affirmative, at the same time displaying a little red, white and blue flag he carried, and which must have considerably astonished the pilot of the British seaplane, evidently the chief controller.

“I did that so he might know we didn’t expect to drop any bombs, or have a part in the raid itself,” Frank explained, turning to his companions.

“They’re all worked up over seeing such a whopping big seaplane here,” remarked Pudge, with a touch of the old pride in his voice. “They’re having the surprise of their lives right now, let me tell you. I’m glad they know that it’s a Yankee machine.”

“But, Frank, as we understand it, all these bomb-droppers don’t intend to go to one place, do they?” asked Billy, as he watched the whirring machines flit past like so many big dragon flies.

“No,” came the ready answer. “When up the coast a piece, there’ll be a division starting inland to damage the railway station and try to get at the supplies the Germans have gathered at Bruges, as well as some other points.”

“Well, what about us then?” asked Billy.

“Yes,” added Pudge, also deeply interested; “do we go on with the seaplanes and keep tabs of what they do up around Ostend and Zeebrugge, or else switch off and go over the land the same as you and Billy did yesterday?”

“I’ve fixed all that with M. Le Grande here,” Frank told them. “He expressed the wish that we might see fit to keep with the main body along the shore, because it is expected the most spectacular feats will be attempted there.”

“Gee! I was hoping you’d say that, Frank!” Billy exploded.

“Suits me to a dot, too!” Pudge followed by saying.

“I hope they are going to start right away,” added Billy.

“There’s a message being sent up by heliograph,” explained Frank. “Of course, we can’t read the flashes, but it’s meant for the man in the leading plane. I expect it will tell him everything is all right for the start.”

He proved a true prophet, for immediately afterward some signal was given that caused the entire assemblage of aëroplanes to cease their evolutions and head in a long double string up the coast.

The boys, despite the clattering of propellers and the humming of many striving motors, could catch the distant wild cheers that the assembled people of Dunkirk sent after them. It was a benison of good wishes, and a hope that the object of the great raid might be fully accomplished.

Frank kept somewhat above most of the aircraft. He had several objects in doing this, chief of which was the design to show that he was in a class by himself, and not to be included in those who had come forth to fight. Besides, it allowed them to observe all that was going on below; as well as being in a position to show the pilots of the fleet a few little things connected with the strange looking Sea Eagle that would cause them to feel more or less astonishment, and envy as well.

“Will you show them something, Frank, now that we have the chance?” asked Pudge.

“It will have to be before we get to the first place they expect to bombard, then,” Frank replied, meaning, of course, that once the work of the fleet began there would be no time for any of them to manifest any interest in the evolutions of the American built aircraft.

When Frank had moved a lever that called for all speed, and the motors were working at the astonishing rate of almost two thousand revolutions a minute, it seemed as though they had left the rest of the fleet far in the lurch. Green flames spouted from the exhausts, for Frank had opened the muffler in order to get every ounce of speed out of the motors.

They could see the pilots of the other seaplanes looking up at them in mingled wonder and admiration, for, like the jockeys of race horses, it is the ambition of every aviator to possess the fastest going machine on the market.

Having secured a free section of space to himself, Frank proceeded to put the wonderful Sea Eagle through her paces. He showed what could be done in various ways, and while possibly most of those other craft were capable of accomplishing similar tricks, the fact was made patent that the superior size of the American made hydro-aëroplane did not act as a bar to the ability of the Sea Eagle to maneuver in a dexterous fashion while going at that tremendous rate of speed.

“Now we’ll have to stop, and mount a little higher,” Frank remarked, having circled around and found himself once more back of the leaders in the procession.

“There go several aëroplanes off to the right!” announced Billy. “I reckon that’s the detachment told off to tackle Bruges and other interior places.”

“We’re coming to Ostend!” Frank told them, pointing down to where the city of the celebrated bathing beach could be seen, with the houses and hotels close to the famous sandy stretch of shore.

There were boats in the harbor, and they must be German owned or they could not have come there. Billy, using the glasses, could see that the most tremendous excitement had seized upon every one in sight. People were rushing in every direction, soldiers as well as civilians; the rays of the sun glinted on cannon that were being hastily changed, so as to point upward.

“There goes the first anti-aircraft gun!” called Billy, as a faint boom reached their ears from far below.

“Watch what the fleet pilots do!” Frank told them.

Apparently the plan had been well worked out, and every pilot knew exactly what was expected of him. Maps of the region had been carefully studied in order that the position of each vulnerable point of attack might be known.

If there was a railway depot which the Germans used every hour of the day, and the loss of which would cripple their transportation facilities, that was picked out to be an object of attack. Here was a mole alongside of which possibly submarines tied up, and its destruction would deprive the enemy of a valuable station. Further on a large shed marked the spot where great stores had been gathered, and if a bomb could only be exploded in the midst, it was going to mean that there would later be a shortage of provisions. An oil tank, an ammunition magazine, a forty-two centimeter gun, such as battered the forts at Liège to pieces, all such were fair objects of attack wherever they could be found. The one order that had been given to every pilot was to avoid destroying the property of civilians as far as possible.

As Frank and his chums looked down from their higher level they saw a sight such as had never before been witnessed by human eyes. The air was filled with a flock of circling, dodging aëroplanes, with puffs of white smoke breaking above, below, and in some cases amidst them, as the guns on the ground were fired again and again in hopes of bringing one or more of the venturesome craft down.

Various explosions far beneath proclaimed that the bombardment from the sky was in full blast. Most of their ammunition, however, would doubtless be kept for the more important base at Zeebrugge, where raiding submarines were wont to start forth on their daring excursions through the waters of the Channel, seeking to destroy British and French merchant vessels or ships of war.

Already the leading seaplanes had passed over the watering place known as Ostend and which before the war had been a famous summer resort. Doubtless their departure would be watched with mingled feelings by the thousands of German soldiers who had been interested observers of this wonderful sight in the heavens. They would also doubtless wonder what was going to happen when the aërial fleet returned, as it surely must, to its base at Dunkirk.

“How about Antwerp?” asked Billy. “Think they’ll take a turn up there, and drop a few reminders on the railway station, or some of the forts they say the Germans have been building up again?”

“I hardly think so,” Frank replied. “This is a raid on sea coast places, as I understand it. They want to strike at the submarine bases so as to upset the plans of the Germans for next week, when the blockade of the coasts of Great Britain and Northern France goes into effect. They’ll do some damage at Bruges and Blankenberghe I expect, just as we shied a few at Ostend; but the main thing will happen when we get to Zeebrugge.”

“I think that must be the place just ahead of us right now, Frank!” called out Billy, who was again using the glasses, bent on seeing everything that occurred; for he realized that they were highly favored by fortune in being given a chance to witness such strange sights.

“Yes, that is Zeebrugge,” Frank admitted. “Now we’ll see something worth while, if no snow squall comes along to shut out our view!”

“Pirates and parachutes,” cried Pudge, “but I hope that doesn’t happen to us.”