It quickly became apparent that the squalls they had previously met were playful little things compared with this one. It buffeted the big seaplane about as though determined to wind up its successful career then and there; and only for the complete mastery which Frank showed over the flier, some terrible accident must surely have ensued.

M. Le Grande was plainly nervous. He realized that in this sort of a wild storm an ordinary aëroplane would not have a ghost of a show. He was also at first inclined to doubt the capacity of the American boy aviator for meeting the strain of the situation.

As he watched Frank manage, however, this doubt took wings. He even began to take note of the astonishing stability of the Sea Eagle, and decide in his own mind that its like had never before been constructed.

Meanwhile Billy and Pudge were virtually “on needles and pins.” They had all kinds of confidence in Frank, and faith in the big plane as well; but that wind did shake things up terribly, and there could be no telling how much worse the conditions ahead of them might prove to be.

None of them could see three feet in any direction. Blinded by the swiftly driven snow pellets, that stung as they came in contact with their faces, they were compelled to bow their heads to the blast, and pity Frank who was forced to stand it without flinching.

Fortunately it did not last very long. Human endurance would have been exhausted had it continued indefinitely, for Frank was becoming more or less weak under the strain, when he heard the experienced French aviator shout in his ear:

“Courage, it is passing by! I can see the sunlight beyond. Courage, my brave boy! You have done magnificently, superbly! I take off my hat to you!”

Yes, they could all see now that the snow was growing lighter, showing the border of the cloud must have been reached. Frank had urged the seaplane on in a headlong rush with the idea of ending the agony sooner, and it was well he had shown such sagacity.

They emerged from the cloud which was soon left far astern. Frank cut down the speed to one-half, for the air was fearfully cold, and all of them seemed to be very nearly frozen.

Once in the bright sunshine again, though there was very little of warmth to it, those who could do so began to slap their arms violently to and fro in the effort to induce circulation. The French air voyager even relieved Frank from his arduous duties as well as possible, so that he could get some life in his stiffened fingers.

M. Le Grande was fairly bubbling over with praise, not only for the splendid way in which Frank had managed his craft, but in regard to the seaplane itself. Never, he told them, had he seen such a supremely satisfactory test made to prove the stability of a flier; and in every particular had the Sea Eagle proven itself worthy of the highest praise.

“Ah! M’sieu!” he went on to say warmly, “with a fleet of such wonderful craft, patterned after this type, we French could soon end the war alone and unaided, by striking terror to the heart of Berlin. I am pleased beyond measure with all I have experienced. The man whose mind conceived this wonder of the air is indeed a wizard.”

“Good for you!” cried Pudge, who naturally was delighted to hear his father spoken of so highly.

Once again they began to take an interest in what they could see far below them. New and varied sights were constantly cropping up as they journeyed on. The character of the country was gradually changing, too, for the dreary stretches of water that marked the inundated lowlands of Belgium near the coast began to merge into dry land. This was high enough to have shed the rains that had been falling during the better part of the winter now drawing to a close.

As before, Pudge and Billy commenced calling each other’s attention to different things that caught their eyes. These were all of an intensely interesting nature and extremely varied.

In numerous instances they were fired at. The faint report of volleys came to their ears as soldiers, in the hope of doing some damage, started shooting, though it must be an extraordinary rifle that could push a leaden missile that far up into the air.

Now and then some anti-aircraft gun perched on an elevation would take a shot at them, but the white puff of shrapnel smoke invariably appeared far below, and told that there was no danger from this source at present.

“It may be a different thing,” said Frank, when they started discussing this failure of the shots to reach their altitude, “when we strike a rough country, for from the summit of a high hill one of those guns could give us trouble.”

“Well, we must climb out of the danger zone then, that’s all,” concluded Billy, as though not worrying himself in the least about such a possibility.

They were now approaching the fighting line that stretched across the country in a zigzag fashion. Everywhere the Germans had dug themselves in as though it was their full intention to grimly hold on to what they had seized, and only allow the Allies to take it after the most desperate resistance.

Eagerly the French aviator was using his binoculars. No doubt he was making a mental map of many things they saw, and would not hesitate to use his knowledge afterward, if he thought it might benefit his side.

Frank winced a little as he thought of that, for he did not wish to be unfair any more than conditions imposed on him. He salved his conscience by telling himself that there was nothing they were observing but what any daring aviator of the Allies might not ascertain for himself by a flight across that section of the disputed territory of France.

“If I saw a German Taube man in trouble right now,” Frank was saying to himself, “I’d be just as quick to go to his rescue as though it were a Frenchman or a British pilot; and that’s what we mean by calling ourselves neutral. I warrant you that ninety-nine out of every hundred adults in the United States, who know about this war, have a leaning toward one side or the other, according from where their ancestors came. But we all wish it was over, and Peace had come again to these countries of Europe.”

There had really been little to proclaim the fact from radical changes in the villages below them, but Frank believed they must have left the Belgian border behind, and were now sailing over Northern France.

On mentioning this to M. Le Grande, he was immediately assured by the French aviator that such was indeed the case, and that though German fortifications still dotted the landscape below, it was the sacred soil of La Belle France.

“Soon will they have to pack up their baggage and set out for the Rhine country, when, in the Spring, the great offensive begins,” the patriotic Frenchman declared, as though the sight of those enemies encamped on the soil of his beloved land filled his heart with anguish.

It seemed as though there was more or less action going on all along the lines of trenches. As those who sped along high above the earth watched, they saw bodies of men shoot forward, to meet with a deadly fire from all manner of concealed guns. Perhaps they would be thrust back whence they sprang; or if the impetus of their advance were sufficient to carry them to the trenches of the enemy, there would ensue a hand-to-hand grapple that was terribly fascinating.

Pudge had to actually pinch himself several times in order to make sure he was awake, and not dreaming.

“To think that I’d ever have this wonderful chance to see what modern warfare is like!” he exclaimed in an awe-struck tone. “There’s the whole picture spread out below as if it might be painted especially for our benefit. Oh! what was that?”

A terrible explosion had apparently taken place. A section of the German trenches must have been blown up with a mine, for in the midst of the smoke they could see the khaki-clad British soldiers rushing pell-mell to occupy the breach before the Kaiser’s forces could recover from the shock, and hurry additional forces up to hold the particular spot.

Such things as that were happening here and there along a line hundreds of miles in extent. It was appalling to the boys to think of such a thing, having so recently come from across the sea, where their native land was basking under the sun of peace, with not an enemy to fear.

The country became more rugged as they pushed on. Still there was no sign of any hostile aëroplane rising to engage or trouble them. In fact, all that day up to now they could not remember having once set eyes on a Taube or a Zeppelin in the air. It certainly looked as though for once they must have had strict orders to keep in hiding until the storm had blown itself out.

“I can see what looks like a city away off yonder,” announced Billy, who was handling the glasses again.

“It is poor Lille, so long held possession of by the barbarians,” said the native aviator, with sadness in his tones; and the boys did not wonder at it when later on they learned to their surprise that M. Le Grande himself had been born and passed most of his life in that city of Northern France.

No doubt, if he could have had his way, he would have enjoyed nothing better than the chance to hurl down such a rain of bombs upon the invaders as must have hastened them back to their own country.

“Will you pass over Lille, Frank?” asked Billy, and there was that in his voice to tell how pleased he would be should his chum give a favorable answer.

“It would be something to say we had done it,” Pudge hastened to remark, showing the trend of his thoughts.

“Yes, we might as well take a look in, and see what the Germans are doing there,” Frank announced. “After which, with a swing around, we can set sail for the fighting line, pass over to ground which the British are holding, and then start for the coast at Dunkirk, and so complete the roundabout cruise.”

The seaplane passenger was staring at his native city through his glasses, muttering to himself in French. They could easily give a guess that these were far from blessings he was calling down on the heads of the Germans, who held on to everything they ran across so obstinately.

They were again made a target for numerous guns, but as Frank had risen to a somewhat higher level, they did not believe there was any chance of a stray missile doing any damage.

So they passed over Lille, and left the sorely stricken city behind them. M. Le Grande twisted himself halfway around, the better to see the last of the place where his heart lay.

It was just at this minute that Frank was heard to utter a cry, and manifest considerable consternation.

“What’s happened?” cried Billy, as quick as a flash; Pudge turned pale and glued his eyes on Frank’s face, which was to him a barometer.

“There’s a slackening up in the feed as though the pipe might be clogged!” exclaimed Frank, in considerable apprehension. “Billy, take a look and see about the amount of petrol we’ve got in the tank!”

Billy knew how to go about this; indeed, it was a part of his regular business.

He had hardly started to carry out Frank’s instructions before he shouted:

“Gee whiz! Frank, it’s just about plumb empty! We must have been hit, and the tank’s sprung a leak!”

“Ganders and gridirons!” cried Pudge in sheer dismay. “Whatever will happen to us now, if we’re forced to land in the midst of the whole German army! Whee! I see our finish!”