CHAPTER XIV.--THE BATTLE IN THE AIR.

The smoke was driving fiercely through the green trees on the slope, and the line of fire was not far in the rear. Every moment the wind gained force, every minute the flames leaped higher and faster.

The foresters felling trees and clearing a space at an advantageous point some distance in advance of the flames were working blindly, mechanically. The heat was intense, the smoke suffocating, irritating, blinding. The shirts of the workers were open at the throat, their coats had long ago been lost as they had been beaten back from one stand to another.

Now and then a worker dropped senseless in his tracks, his lips cracked with the heat, his face blistered, his tongue lolling from his smarting mouth like that of an overworked horse. Then the men who were able to move and understand would carry him back to a spot of supposed safety and return to re-engage in the almost hopeless fight, the battle which the flames were winning in every charge and sally.

The aeroplane, after a narrow escape from destruction, landed on a little rise of ground back of the working line when the wind lulled for an instant, and hope shone in the faces of the astonished men who gathered about to greet the unexpected arrivals.

"We can master it," Green, the leader, said, after many questions had been asked and answered, "if we can be supplied with water. We wasted our supply wetting our clothes a long time ago, and are suffering."

"Get us water," shouted another, "and we'll win yet."

"There's a spring three miles away," Green went on, speaking in Ned's ear, for the roaring of the flames drowned all ordinary conversation. "If you can take our water bottles there and fill them we can beat this blaze. If you can't we've got to retreat and let the whole district burn over."

"I have very little gasoline," Ned replied, "but I'll try."

"We sent two men out not long ago," Green continued, thrusting his scorched face close to the boy's. "We sent them out with water bags, but there are no trails, and It will take them hours to make the spring and return. With your aeroplane you ought to do it within half an hour."

"Fire fighters marooned without a supply of water, or a trail cut to a spring!" shouted Frank, scornfully. "Great head some one in authority has!"

"There are no trails, no telephones, no horses!" cried Green. "It looks as if the government sent us here to die. Hurry up with that water."

"If the gasoline holds out," Ned said, loading a dozen water bags on the machine, "I'll be back here in less than half an hour, bar accidents."

"There is plenty of gasoline back there in the shanty," cried Green. "We have been using it lately in starting back fires, but the wind is now too strong for that. Get a move on, and take all you want."

In a short space of time, but not without great risk, the tanks of the aeroplane were filled, and then Ned took in the general situation in the sky. The wind was blowing in puffs, but it was certain that a miniature tornado was at hand. He thought he could reach the spring, which had been described as lying to the southeast, but was not certain that he could make his way back.

He believed, however, that by flying either very low or very high up, so as to get all the protection possible from the mountain, or escape the sweep of wind just above the fire, he might be able to bring in one load of water before the worst of the wind storm came. He knew that it was an almost unheard of thing to even try to navigate the air in such a gale, but human lives were at stake, and he decided to try.

"You'll have to help me up against this wind," Ned said to Green. "If I start with the air current I'll be carried too far to the east before my power begins to become effective. If I can hold my own against the wind until I get above the smoke I think I can win the game."

It was a desperate expedient, but it appeared to be the only possible one. If the men had water they might succeed in stopping the fire and saving millions of dollars worth of timber. If the fire gained the upper hand they might lose their lives. The men cleared and smoothed a path for the run of the wheels, by great exertion sent the machine along at good speed, and then stood and watched it with anxiety depicted in their faces.

The great white bird quivered in the face of the wind, but the motors were true to their duty and the rudder held. To turn about in the face of that rush would be impossible, so Ned worked his levers guardedly and kept the wings as level as he could. Now and then a swirl of heated air would shake the hopes of those watching below, but in the end the aeroplane drifted slowly ahead, up, higher up, and was lost in the smoke.

"The lad is worth his weight in gold!" shouted Green. "He'll do it! I know he'll do it!"

"Powerful motor," one of the foresters said. "When we saw the machine last she was actually holding her own against the wind."

This was, indeed, the fact, but the wind was not as strong in the higher levels as at the upper limit of the heat from the fires. A great fire usually brings a great wind, as those who witnessed the burning of Chicago and San Francisco well know. The hot air rises, forming a partial vacuum, and the colder air rushes in.

Ned and Frank gained the spring, filled their water bags and started back. It was no easy task to land near the spring in that whirl of wind, nor yet an easy task to get the aeroplane into the air again, but the feats were accomplished. Often after that exciting day the boys declared that they had no idea how they ever did it.

"We were excited," Frank would say, "and took chances, everything worked in our favor, and we loaded the water. We knew that lives were at stake, and it seemed that we had the strength of a score of men, and the cool heads of men far beyond all excitement. I never saw anything like the way Ned handled the levers. The wings and the rudders seemed to me to work on a brain suggestion rather than on a movement of the levers."

But the most difficult part of the journey still remained to be accomplished after the water had been secured. The 'plane was much heavier and did not respond so readily to the hand of the driver, and the return course was quartering against the wind. Ned, however, did not attempt to move directly toward the destination he sought.

Instead he sailed off to the south, working west as much as possible. He tacked as a yacht tacks in the wind and came near upsetting several times. He found it impossible to sail low on account of the eddies and currents created by the heat, and so lifted the machine far up into the air. It was better sailing there, and he managed to get as far west as he thought necessary.

But he could not see the landing place. Below was an ocean of smoke, the waves heaving in the touch of the wind, the edges now and then tipped with flame. Above the sun smiled at him, and the birds flew excitedly about, peering down at the threatening roll of clouds.

"I'm afraid," Frank said, grasping an upright and clinging to the water bags.

"I never was so frightened in my life," Ned called back, lifting his voice so that it might be heard above the snapping of the motors.

"I didn't finish," Frank called back, his heart thumping loudly. "I wanted to say that I was afraid we'd sweep past the workers when we descended into the smoke and the swifter breeze near the earth."

"I said just what I wanted to say," Ned answered. "I never was half so scared in all my life."

Yet his hand on the lever was steady, his brain was as cool as if he had been sitting in the Wolf Patrol club room in New York. He knew that the dip of a wing a foot lower than he intended might send them both into the blazing forest below. He was afraid, but not with a shrinking, physical fear, but afraid because he understood the peril he was in--because he knew that upon his efforts depended the lives of the heroes in the heated hell below.

"We've got to go into that mess of smoke, I suppose?" shouted Frank.

"There is no other way," Ned called back. "We've got to dip down low enough to see the line of fire and take our chances on landing where the fighters are. You understand that they are farther to the east than when we left them?"

"Of course they have been driven back," Frank said. "I never thought of that. We may not be able to find them at all."

Ned shut his teeth and settled his jaw.

"We've got to find them," he said.

A long, sullen roaring, like the beating of waves on a beach in a storm, now reached the boys' ears, even shutting out the chattering of the motors. It came from the west, and passed along, as it seemed, below the level held by the aeroplane, now high up in the air.

"If we don't get down there pretty soon," Ned said, shouting, "we will be too late. That wind will join the different fires and make one roaring mass of the whole northwest. I wish I knew just how far the foresters have been driven back."

"Do you know where to look for them, north or south?" asked Frank.

"There is a peak to the west and one to the east," was the reply. "They are on a line with the two. But the trouble is that we can't see the peaks after we drop down into the smoke."

"There appears to be a little lull in the wind now," Frank said, shutting his lips tight, as a man does when about to make a sudden plunge into unknown waters.

The remark was suggestive. Ned knew by it that his chum had braced himself for the dash.

"Here we go, then," Ned replied. "Remember that we'll go about eighty miles an hour when I turn the motor on full head, and that we can't be more than five miles from the spot where we left them, so keep your eyes out."

The aeroplane dipped gracefully as Ned touched the lever. In a minute the boys were surrounded by smoke. It was hot smoke, too, and made breathing difficult. Their eyes smarted until their faces were wet with nature's protest against such irritation of the organs of sight. The chuck-chuck, snap-snap of the motors was in their ears, the seats they occupied--frail rests between life and death--shivered under the pulsations of the machine.

Now and then the aeroplane dipped frightfully, but the wings and the rudders brought it back again.

"Can you see the earth yet?" asked Frank, In an awed tone, which sounded like a whisper in that clatter.

"We seem to be over the fire," Ned returned.

And that was all. There was no need of conversation. In all their lives they would never be so near to a frightful death as they were then.

First they caught sight of a rocky ridge. Ned knew where that was, and realized that he was still in the direct line of the workers. Beyond this ridge, he knew, was a valley, so he must drop down. The workers were on a level beyond the valley, a great plain of fir and pine between gigantic ranges of the Rocky Mountains.

The aeroplane trembled as she dropped, swiftly, apparently straight down. Frank grasped his upright and prepared to spring out of the wreckage when it fell, if there was anything to fall from after the trees had had their way with the frail machine.

The smoke was blinding. Nothing could be seen but smoke for a time. Then the dark gray clouds turned red, and Ned knew that he was nearing the advance line of the fire, and that it was mounting to the very tops of the giant trees on the plain--or elevated plateau, rather, for, though comparatively smooth of surface and heavily timbered, it was far above sea level.

If you look on an enlarged map of northern Montana you will see that the Rocky Mountains do not consist of one great, massive range. There are ridges and valleys, and plateaus extending for hundreds of miles along the British frontier. There are peaks from which the snow never disappears, and there are timber lines which crawl almost to the summit of other peaks. There are fertile valleys where cattle grow fat, and great gorges where beasts of prey await their victims in thickets.

It is the timber on this great stretch of country that the United States government is trying to save.

The heat was blistering now, and Ned feared for the safety of his gasoline tanks. At a motion from him Frank removed his coat, carefully, for a slight movement in the air is sometimes productive of disastrous results, placed it over the tanks, after a great effort, and managed to saturate it with water from one of the bags.

Through the smoke a line of tree tops now came into view, low down, and the boys knew that they had passed the fire line. Ned tried to slow down, but found that he must keep the motors going in order to retain control of the machine.

"There's a clear space ahead!" Frank shouted, and Ned dropped. Then a giant trunk obtruded itself, and the boy tried to dip and whirl so as to dodge it, but the pressure of the wind was too strong.

The machine headed straight for the tree, which seemed to Frank to be about a thousand feet high.

"Hang on to the first thing that comes to your hands if she strikes!" Ned shouted. "But stick to the 'plane as long as she is clear. There may be a current of air which will sweep us away from that tree."

"Here's hoping!" Frank gasped back, and then the smoke shut out the view, making the situation doubly dangerous.