“It has been a leak, for even now it is dripping down!” exclaimed the French aviator, pointing his finger at the bottom of the petrol tank.

Pudge and Billy held their breath. Everything would depend on Frank, who must know what was best to do. They might plane downward, and manage to make some sort of a landing, but that would mean capture by the enemy. The presence of the French aviator would bring the wrath of the Germans down on the heads of the boys, and as a result they would be made prisoners of war.

Not only that must follow, but the precious seaplane would fall into the hands of the Kaiser’s men. Such a possibility could never be endured. M. Le Grande would be ready to try something desperate before such a catastrophe could be countenanced.

Frank had to do some pretty swift thinking. Fortunately he was not the one to lose his head in the presence of unexpected danger.

“We must make a furious attempt to get across the fighting line, which is some miles away from here at La Basse!” he exclaimed. “When we descend, it will be in the rear of the British forces, where we can be safe!”

“Let her go, Frank!” said Billy excitedly.

“Yes, for all she’s worth!” added poor Pudge, as well as he could, for his trembling lips made any sort of utterance difficult.

Frank had not waited for this to turn on all power. At the time of the discovery, with regard to the loss of their precious liquid fuel, the seaplane had been headed just right, so all that appeared necessary was increased motion.

The motors responded to the call upon their reserve powers. Again, with muffler cut-out wide open, and the green fire issuing from the exhausts amidst a roaring sound, they rushed through space.

What speed they were making none of them thought to notice by glancing at the aërial speed meter, but it must have been something like ninety miles an hour at the very least, possibly much more.

Here was another supreme test which the French aviator must be sure and take note of. He did not show any particular signs of alarm, though he was plainly excited.

Everyone was gazing ahead, their only aim being that they speedily arrive at the line where the gray-clad Germans were standing off the khaki-clothed soldiers of King George.

Such was the state of their nerves, that seconds seemed to drag like minutes. Billy was trying the best he could to focus his glasses so as to announce the glad tidings that they were rapidly nearing their goal; but he found it hard work because of the shaking of the seaplane under the forced pressure.

“It’s there just ahead of us, Frank!” he finally shouted. “Keep her going only a little while longer, and we’ll be all right!”

“Hurrah!” cried Pudge, rather feebly it must be confessed, for the wind fairly took his breath away.

Frank had not only kept straight on but at the same time he was commencing to head downward. There was a strong possibility that at any second the motors might refuse to work, being deprived of their feed, and in consequence the big seaplane would have to start earthward by the method popularly known as volplaning.

When reduced to that method of landing, Frank wanted to be as well down as he could with safety allow the seaplane to drop. What little danger they risked of being struck by some shot sent by the astonished Germans was not worth while considering. The great speed they were making would in itself serve to protect them from this threatening evil.

It was a critical moment for the aëroplane boys, and one that none of them would be likely to forget soon. They could notice that the rattle of the exhaust was growing more and more deadened. That told them the end was very near and then the last feeble effort of the motors would end in a total collapse.

“A pint of gasoline would see us through with flying colors!” exclaimed Billy.

“Just to think of it,” cried Pudge dismally, as though the thought of falling into the hands of the Germans and being treated as a prisoner of war filled his heart with dismay.

“On! on! keep her going, young m’sieu!” almost shrieked the Frenchman, as he half stood up in his great excitement, and turned his gaze from Frank to the prospect before them.

Frank had changed his plan of action. He no longer pushed the motors to their utmost. The muffler, too, now shut off those spiteful looking greenish flames, and the rattle was silenced.

In truth, Frank, in the belief that if they could only keep afloat, their momentum would be sufficient to carry the seaplane across the line of trenches, was trying to conserve every atom of power. He asked nothing more than this, and would be willing to take his chances of making a fairly successful landing, though a craft of that description was never intended to start or finish a voyage save on the water.

Pudge became more alarmed, now that the shrill clatter of the exhaust had been silenced, for unlike Billy he had not grasped just why this had come about.

“Oh! will we make it, Frank?” he cried in an agony of fear.

“I think so,” the pilot told him steadily.

“But she’s swaying right now as if ready to give up the ghost and drop!” Pudge complained in a strained voice. “That rattle has stopped. Why is that, Frank?”

“I did it so as to keep what energy we’ve got as long as we can,” he was told.

“We’re doing nobly, young m’sieu!” called out M. Le Grande.

“Yes, there are the trenches just ahead of us!” added Billy. “Listen to the rattle of rifles, will you? And I can hear cheers too, hearty English cheers. See them jumping up in plain sight and waving to us, boys! A little further, Frank, and you can volplane if it’s necessary, because we’ll have crossed the line and be in safety.”

But the puttering of the motors told that they had arrived at the last stage of labor. A gas engine cannot run without fuel of some sort, and the vapor now being fed was of an inferior quality, so that the energy became less and less.

They were at this critical time almost directly over the German trenches, and so close that they could see the soldiers pointing up at them, even without the use of field glasses or binoculars.

“Oh! did you hear that bullet hum past then?” ejaculated Pudge, who had ducked his head in an involuntary way as though he would avoid contact with the random lead, just as some nervous people start with each flash of lightning.

Other missiles were also winging along through space, showing that the seaplane, in its mad race for a safe landing, must have already descended a considerable distance under Frank’s manipulation.

Strange what queer thoughts will flash into the mind when under such a stress as this. Frank afterward laughed to remember how he was determining then and there, that if ever he had occasion to make another aërial voyage above hostile armies, where he might be subject to a bombardment, one of the things he meant to see about before starting was that he carried a bullet-proof petrol reservoir along with him.

Suddenly the motors ceased working, as the supply of gas came to an abrupt end. They were by now over the British trenches, where the men were shouting all kinds of hoarse salutes, though compelled to again hastily seek shelter in their pits, as the Germans had opened fire on them.

Frank had but one way open to him in order to reach the ground. This was to volplane swiftly, as he had many a time done after shutting off all power, and when a certain distance from the earth, by suddenly working his planes, cause the aircraft to assume a horizontal position instead of a vertical one, after which would come the straight drop.

Just what sort of a jar must accompany the landing would depend, in a great measure, on the distance they were up at the time, and the skill shown by the pilot in managing these things.

It is always deemed a spectacular method of descending from an upper level, and not as dangerous as it may appear to those who are unfamiliar with the working of aircraft. Frank had practiced it many a time, and in an ordinary aëroplane, with its rubber-tired wheels to run along the ground, would have thought nothing of it. When he had to land with a seaplane, never meant for such a purpose, it was a “horse of another color,” and might be considered a very ticklish job.

The ground seemed to be rushing up to meet them as they fell. Pudge shrank back as though he could already feel the terrible shock of the contact, should they continue to make that swift downward progress.

But Frank was ready to change the planes, and in this manner alter the conditions. They would act as a stay, and bring their headlong rush earthward to an end. After that it would simply be a dead weight drop, and perhaps not so hard as to smash anything about the seaplane beyond repairing.

Before Pudge had time to take another full breath it was all over. They had swept down beyond a low hill, on top of which stood one of the windmills so often seen in Holland, Belgium and Northern France, with its broad arms standing motionless, and the tower showing signs of having been struck by more than one solid shot during some tempestuous battle for the rise.

With slackening speed, the seaplane followed the descent, and then came to almost a full stop at its base. After that it dropped straight to the ground.

The shock proved to be rather severe, and Pudge was even jolted from his seat, falling in a heap close by. Frank jumped out and was immediately followed by Billy and the French air pilot, all of them perhaps considerably shaken, but apparently none the worse for the rough experience.

Frank first of all sprang over to where Pudge was wallowing. The fat boy sat up just as Frank reached his side.

“I hope you’re not hurt much, Pudge?” cried the pilot of the Sea Eagle, as he hurriedly bent over to assist his chum to gain his feet.

Pudge started to feel himself all over. He ran his hands along his fat sides, and then down each leg; after which he proceeded to announce the result.

“Nope, don’t seem to have any serious contusions or broken bones that I’ve been able to find. Guess I’m all whole, Frank, as I hope the rest of you are. But how about the poor old Sea Eagle; is she smashed beyond repair, do you think, Frank?”

“I haven’t taken a look at her so far,” the other told him. “What little damage may have been done can be easily repaired, once we get her taken by wagon to our hangar at Dunkirk.”

“Good enough!” cried Pudge. “I was worrying more over the seaplane than about myself, I do declare. When we can get in touch with the commander at this section of the British forces, we might be able to commandeer some sort of wagon on which the machine can be packed, after we’ve taken it to pieces, and transported it to town. Our good friend, M’sieu Le Grande can tell them the plane now belongs to the French Government, and that a heap depends on its being taken to Dunkirk.”

As they reached the spot where the big seaplane lay like a wounded bird, it was to see the Frenchman and Billy come crawling out from under the wings.

“What’s the extent of the damage?” asked Frank immediately.

Before Billy could start explaining, there was a sharp sound heard, and Frank actually felt the wind of a bullet whizzing past his cheek.

“Duck down everybody!” he exclaimed, suiting his actions to the words, and pulling Pudge after him. “We’re being fired on by somebody concealed in that old windmill base over there. Try and find shelter if you can, Billy!”