Of course the bombers were also fitted to ward off attack, each being armed with two machine-guns, one forward, and the other aft where the man who handled the bombs could manipulate it. Slower and much less agile than the fighting planes, they were expected to defend themselves but not to attack.
The advance had slowed up, but not entirely stopped while the battle was joined. As yet no bomb had been slipped from its leash, for the right moment still held off.
Looking down Jack could see where the searchlights that sent such broadening streamers aloft were stationed. He could also make out a dim pile that must be the German fortress, strengthened particularly to hold up the Americans, even as that at Verdun had held up the Huns.
Let the "Archies" bark below and the shrapnel burst all around them as it pleased, no one in all that vast armada of the air was paying the slightest attention to such things. They all, in their carelessness of danger, seemed to themselves impervious to the storm of flying missiles.
The slower-moving bombing machines bore the brunt of this furious onslaught, and Jack could tell that the wings of their plane were being cut by the bullets.
It was almost a miracle that so far no one aboard any of the ten big planes seemed to have been struck; or if such a thing had happened the injury did not appear to be serious. They continued to move forward as if all the Huns in Northern France, backed by every sort of gun that could hurl shrapnel aloft, would not be sufficient to stay their progress.
Presently, however, the formation was broken at a signal. To try to maintain it any longer would be little short of suicidal, for the gunners below were getting their range better, and the bursting shells came alarmingly close now.
Tom kept his eyes constantly about him. Each bomber tried to keep at a given altitude in making the evolutions, since in that way they were better able to avoid a collision that would be fatal to both machines.
At last Tom caught his signal and as he headed straight for the spot over the fortress he gave Jack the sign. The bomb slipped from its sheath, and was instantly lost to sight in the smoky atmosphere below.
Already they had had their ears shocked by numerous discharges, as others among the Americans shot their missile earthward. It was terrible to look down at that crisis in the attack. The whole world seemed on fire beneath them, what with the exploding bombs and the myriad flashes coming from the German guns at work.
Jack was disappointed because in this vast inferno he found it utterly impossible to tell where his special messenger struck. He knew, though, that he had been in a fair position for a hit when given the word, and on that account never found any reason to doubt but that it had given a good account of itself.
After delivering his fire Tom swept off to one side so as not to interfere with another bomber who might occupy a higher level, and be advancing to the attack.
Presently when the turn of the air service boys came again they would be ready to send down the second "bundle of concentrated destructiveness"; and later on there might be a "clean-up call" that would exhaust the stock carried by each plane.
Meanwhile, given a chance to look hastily around at other factors connected with the extensive engagement, Tom discovered that there had been at least one victim besides the initial one.
A plane was dropping swiftly, swinging this way and that, turning over and over, and showing signs that the pilot's hand no longer controlled the levers. He was unable to make out whether it was an enemy plane or one of their own convoy; but the doom of those who happened to be belted to the seats was undoubtedly sealed.
CHAPTER XVIII
FAVORED BY FORTUNE
THE Huns soon discovered that they were up against an intrepid enemy.
When they so boldly attacked the Yankee fleet of raiders, as Jack expressed it in his boyish way, they had "bitten off more than they could chew."
They had dropped back a bit and were trying to annoy the Americans all they could with as little damage to themselves as possible. If their last stronghold was doomed to destruction under that rain of mighty bombs, any self-sacrifice on their part could not ward it off, and so what was the use?
The end seemed to be approaching, for the Boche plainly showed he had had enough of the fighting. One last combined attack all along the line that would likely put the enemy to flight, and then for the signal that would spell "homeward bound," a magical phrase with voyagers of the air just as it is with sailors of the salty seas.
Finally it came. The great battle was over.
The air service boys rejoiced that the victory was won.
The roar of guns from below had ceased, and as the Yankees above could not find any enemy plane against which to pit their strength, they, too, no longer scurried this way and that, each one like an avenging Nemesis.
Looking down Jack was appalled at what he saw. It seemed almost as though the end of the world had come. Huge volumes of acrid smoke slowly swept along on the night air, with here and there a lurid tongue of angry flame, looking like a serpent's tongue, stabbing the gloomy curtain.
He had seen vivid pictures in colors of an eruption of Vesuvius, and to his mind this presented just such an appalling spectacle. There could never be any doubt regarding the awful power of those latest of Yankee bombs. The German stronghold that an hour before had stood in arrogant pride, meant to be a stumbling block in the path of Pershing's victorious army, had been so shattered that it would hardly be noticed in the general advance of the oncoming host of boys in khaki.
But there was the signal to gather once more in formation of twos for the homeward journey. There would always be a chance that the furious Huns might gather a fresh force of aerial fighters to make one last assault on the columns before admitting defeat; and it was to be ready for this that every possible precaution must be taken.
Then the fact became apparent that the return was not to be made with an undiminished force. There were no longer exactly twenty planes to fill out the double column. Some were missing, having fallen in the last desperate attack of the foe, when a perfect whirlwind of fighting had taken place.
Tom noticed this almost immediately. At least one battleplane was absent, if not more, and the companion bomber that had occupied with them the place of honor at the tail of the procession also failed to come to its place. Perhaps the very plane he had watched drop and wondered about was one of these missing ones.
Jack, too, looked down upon that vast smudge of smoke and shooting flames with a new feeling gripping his heart. It no longer represented merely the disappointed hopes of a Hindenburg and a Ludendorff; it was not to be considered only a fortress annihilated by American pluck and ingenuity; there was a sadness in Jack's parting look now, and for a reason. Down there brave American boys had gone to their fate, after battling to their last breath for the right. In that blanket of smoke and amidst scattered stone and timbers they had found their tomb, nor would those loved ones far across the sea ever know where to look for their last resting place.
On the roll they would be marked simply as "lost when on perilous duty", and that brief inscription must ever be their epitaph. None more glorious was ever inscribed on monument of granite in a city's beautiful cemetery; and the Nation would always do honor to their memories.
But the air armada was off once more.
Jack put these thoughts from his mind. They had not expected to carry out their ambitious plans without incurring losses. The price had been paid, and those who came through in safety might congratulate themselves on their good fortune.
Headed for the home camp they left that shambles behind them, for it seemed certain that many Huns must have perished when the fortress was destroyed so completely.
Then all at once Jack remembered something. Tom had almost as much as promised that if half a chance arose while on the way home he meant somehow or other to get "lost" from the main column.
It might not be very hard, seeing that they came at the tail of the procession, and those just ahead would hardly notice the fact if at some time or other they should lag, and vanish from sight. It might be taken for granted that they had simply fallen a little behind, and by putting on a spurt of speed could at any time easily catch up.
At any rate the expedition would not delay, waiting for those who tarried. In an affair of this kind the rule was "every tub on its own bottom," and if accidents occurred the unfortunate plane must drop out, and take its individual chance of getting through in safety.
Jack was wondering just how his chum would act in order to bring about this separation. Hence he was not greatly surprised when Tom called out aloud, so that he could make his voice heard above the incessant whirr of motors added to the buzz of many propellers that filled the air with noise:
"Jack, something seems to be wrong with our engine."
"You don't say!" ejaculated Jack, accompanying the remark with a wide grin; for he suspected that this was only the ruse he had been anticipating.
"I don't seem to be able to get along as smoothly as I did before,"
continued the pilot.
"Why, it's a fact that we are letting the others outrun us some, Tom.
Wouldn't it be just too bad if they went off and left us in the lurch?"
"No joke about it, Jack. Something is really going wrong, and I imagine I'm getting a poor supply of gas. Take a look at the tank, will you, and see if it's all right!"
At that Jack ceased to chuckle. He realized from what the other said that he meant it seriously. Accordingly Jack bestirred himself to carry out the instructions of the pilot, which he was best able to do from his position aft.
A brief interval of silence followed, save for the constant hum of the machinery and the whirling propellers. Then Jack uttered a loud cry that expressed both astonishment and alarm.
"Tom, you guessed it!" he called. "The blooming tank is empty, and we're feeding on the scant reserve in the smaller tank!"
"Try to find out if a bullet cut a hole in the tank, and let our juice run out!" Tom now ordered.