The Boy Volunteers with the French Airmen

"Necessary how?" asked Ralph, in surprise.

"In determining distances, for one thing," answered the lieutenant.

"A watch to tell the distance?" asked Alfred incredulously.

"Yes, indeed," responded the lieutenant. "If you saw a puff of smoke in the distance, and shortly thereafter heard a boom, the distance could be determined almost instantaneously by roughly calculating 1,200 feet for every second. You see, the clock there has a second hand, which is very plain, for that very purpose."

"But suppose there is a regular battle on, it would be hard to tell about the boom from any particular gun, wouldn't it?" asked Ralph.

"Quite true; in such a case it would be useless for that purpose. Another use is in signaling," continued the lieutenant. "For instance, in sending information to a battery, arrangement is sometimes made to flash the distance by means of second intervals."

"How is that done?" asked Alfred, now growing intensely interested in the details of the dashboard mechanism.

"It is an easy matter to signal numbers," answered the lieutenant and a favorite plan is to fly over the area where the enemy's battery is located, then flash at that altitude. The gunner will take the angle, set his piece and fire, the aviator, meanwhile, noting the course and effect of the shot. By means of the watch he can determine the distance, counting either by the time of flight of the missile, or by the elapsed time between the flash of the gun and the landing of the shot.

The altimeter is another very important part of the equipment. It is a device which tells at a glance how high the machine is flying, and Ralph looked at it with a somewhat doubtful expression. The lieutenant saw the questioning lines on his face, and instantly divined the reason.

"You are in doubt whether the altimeter can be relied on? Am I correct?" he asked.

"Well, I suppose it is all right, but almost every time we have been up and took the readings, we found we were actually hundreds of feet less than the altimeter actually showed, so I am wondering if it is possible really to tell the exact height by that apparatus," remarked Alfred.

"Yes, I understand what you mean," replied the lieutenant. "The other day, when we made the long flight from Bar-le-Duc, the device we had showed 900 meters, for it was an automatically registering barometer, as all of them practically are. When we returned I noted on the report book 872 meters. Did you notice that?"

"Yes, and I wondered at it at the time," said Alfred.

"I knew that the general altitude of the country at that place, as indicated by the topographical charts, was 28 meters above sea level so I merely subtracted 28 from 900, and that showed how far up above the land we really were," said the lieutenant.

"Of course, it's a satisfaction to know how high one is flying," said Ralph.

"It is not only a satisfaction, but it is an absolute necessity for an aviator to know how high he is flying, if his mission is to convey any information to the batteries in the rear," said the lieutenant.

"And how is that done?" asked Alfred.

"By a system of triangulation," he replied. "In a few days we may have an opportunity to use the system, and I will explain it then so you can quickly grasp the subject."

The air speed indicator was another interesting device, but at that the lieutenant shook his head as though doubting its general value.

"Don't you think it's accurate?" inquired Alfred of the officer.

"Oh, yes; it is as accurate as it can be made. In fact all devices, which are used to indicate the speed of the wind, are nearly perfect. That is not the difficulty. When it is used on a flying machine several new things enter into the problem, which makes it difficult for the instrument to be truthful."

"What is the main trouble?" asked Alfred.

"Well, suppose we are starting a flight against a wind, which is moving at the rate of, say, ten miles an hour," answered the lieutenant. "While in flight we note that, going against the wind, the air speed is sixty miles. Now, if we happened to stop suddenly so we were poised in the air, the indicator would show the air speed to be ten miles, so that we were really going only fifty miles. If, now, the machine is turned so that we are going at right angles to the movement of the wind, although we may be going actually through the air at a speed of seventy miles an hour, the indicator does not register the air speed at all, because it is in such a position that the air does not affect it and the only indication we have is the speed of the air relative to the movement of the machine,—or, to put it in a better way, I might say that the instrument only registers, in reality, the speed at which the aeroplane goes through the air, and no more."

"But is that the only way to tell how fast we are going?" asked Ralph.

"The best test is to take the engine revolutions. A certain machine after it has been properly tested in a calm, and also in wind currents of different velocities, will show a record of speed with the engine running at certain revolutions. An experienced aviator can judge pretty well, by experience, what the speed of the wind is, and, knowing the propeller speed, and the direction he is going relative to the wind, he can make a fair estimate of the speed of the machine."

CHAPTER X

A THRILLING EXPERIENCE IN THE AIR

It was with feelings of joy that the boys stepped out of their tent the following morning to learn that the lieutenant had decided on a trial spin in the forenoon, preparatory to the real start, which was to take place at two in the afternoon. The engine was turned over, and the machine held down while the usual hour's running test was going on. Everything seemed to be in order, the engine was stopped and another inspection made when the lieutenant gave the order to mount the machine.

In this type of military machine the swivel gun is at the extreme forward end, and the pilot directly behind the gunner, and at a slight elevation above the gun. Both gunner and pilot are housed in, and in most cases strapped to the body of the machine to prevent any accidental falling out, as there have been numerous accidents due to men being thrown from their perches.

The boys found ample room in the forward pit, and at a word the machine was released and glided forward. The new machine gave them a sensation different from the former one, as it appeared to ride more easily and steadily. In fact, there is just the same difference in the motion of flying machines as there is in autos, some, the small machines, seeming to glide over the ground and impart every bump to the occupants, as might be expected of a light machine.

A heavy flying machine, however, seems to move along with the utmost ease, and does not sway from side to side when sailing through cross currents. Naturally, such a machine is a more stable base for machine guns as well as for observation.

Alfred's particular hobby was kodaking. On this occasion, the first time he had an opportunity, he prepared himself with a camera. The lieutenant, learning of Alfred's penchant in this direction, had a regulation government instrument sent over, and attached to the machine, to Alfred's surprise.

Before starting out, the lieutenant said: "I want to give you some points now, in using the camera. Photographs, in order to have any military value, must be identified,—that is, they must be made at such altitudes, and with reference to certain marked characteristics on the earth, that we may be able to place them on the topographical maps of the particular section, and thus verify them day after day."

"What do you mean by verifying them day after day?" asked Alfred.

"I mean by that to see what changes have taken place in the same view between the taking of the two pictures," replied the officer.

"Well, what possible changes could take place in a day or two?" asked Ralph in astonishment.

"A great many, and very important ones, too," answered the lieutenant. "The camera sees what the eye does not notice. If a picture is taken of a certain section today, and the following day another picture is snapped, a comparison of the two will show whether or not there has been a movement of troops, or, whether or not a certain undistinguishable object was something movable, or not."

"Is that the way the map of the enemy's country is made up?" asked Alfred.

"Yes, and every detail is noted, so that when you commence the work be careful to notice something which will distinguish the exact place where you are located; also put down the direction of the flight over that same area, and the altitude at which we are flying."

As the machine glided over the treetops and the village on the northern border of the Meuse, the sun shone out with intense brilliancy. They were going directly east, and both boys turned toward the lieutenant, their eyes seeming to say: "So you are going to take a peep at the front, by way of experiment?" which was exactly what the lieutenant purposed doing.

The altimeter now registered 1800 meters, considerably over a mile high. From that point they could see to Verdun, and thirty miles east of Verdun, could be noted the blurred outlines and surroundings of Metz, that greatest of all fortified German defences. On they went for nearly three-quarters of an hour until a stream of some magnitude appeared to the east, which they soon crossed.

They afterwards learned that this was the Mosel, which flows through Metz. The latter city now loomed up so it could be plainly seen, and to their right was another town, Nancy, a fortified French place. They were about midway between the two places.

Suddenly an aeroplane appeared to the right, and the lieutenant turned the machine in that direction. The boys were relieved to see the great circle on the control planes of the machine in the distance, which showed them it was a French reconnoitering airplane. In the east several other machines were noticed hovering about, and the lieutenant at first headed directly for them, but he soon turned to the north.

Below were seen numerous flashes of guns, and they knew from this that the fighting lines must be along the river. The most startling thing which occurred was a tremendous explosion that seemed to be right in the machine itself, and they looked around startled at the suddenness of it, for everything seemed peaceful enough to them at that altitude.

The lieutenant turned the machine, however, as he apprehended more trouble, now that the gunners below had so luckily secured a fair range. The first shot was followed in another moment by another, and the lieutenant now began to dart the machine back and forth, and turn it in short, sharp circles.

Another explosion took place, this time remarkably close, and pieces of the flying machine came down, and brushed past the boys. The lieutenant shook his head, as the boys glanced back. The machine was now circling around, a peculiar manoeuver, the boys thought, as they looked at each other for a possible explanation.

Ralph looked back, and noticed that the lieutenant, with an alarmed look on his face, was constantly glancing back to the tail planes. The steering lever seemed to be jammed. Ralph had an idea that something was wrong, and crawled over the body until he was alongside of the lieutenant. The latter pointed to the control lever, and Ralph understood.

Without waiting for instructions from the lieutenant, he cautiously made his way along the chassis, following up the wires which were indicated by the lieutenant. Within four feet of the tail plane Ralph halted. Then, reaching down, he succeeded in grasping a dangling wire, and held up the end for the lieutenant's inspection. After several attempts he found the other end of the wire, which had been severed by a shot from a shrapnel shell.

The ship was still circling around, so without waiting to repair the break Ralph turned the rudder, and, glancing at the lieutenant, saw the latter smile, and then by motions direct him to give the control plane a still further push in the right direction. It was impossible for Ralph to hear anything the lieutenant said, but as soon as the airplane was fairly headed for the west, the power was shut off, and the machine began to descend.

"Good boy!" shouted the lieutenant. "Can you fasten them together?" he asked.

"I am afraid not," replied Ralph. "A piece seems to have been shot away. But I can take care of it if you will only direct me to pull it to the right or to the left."

"All right, then. Do you see that great patch of green, directly beyond the castle?" asked the lieutenant.

"I can see it plainly," replied Ralph. "Shall I steer for it?" he asked.

"Oh, no. We must come up from the south. Note the direction of the wind from the smoke. Make a long sweep. We are now at an altitude of 1200 meters. We can volplane twelve kilometers from this height," remarked the lieutenant.

The turn was made to the south in a long sweep, Ralph continually glancing forward to note the direction indicated by the lieutenant.

"Now straight ahead, and hold steady."

They were now rapidly approaching the earth; the machine gliding over the tops of the trees at the border of the forest that ran along the river bank. To their right, across the river, was a large town, Pont-a-Mousson, and the castle ahead of them was a large school, from which even then hundreds of children were emerging, and excitedly rushing toward the approaching machine.

Down went the machine at a sharper angle; then, when close to the earth, the rear control was sharply turned, and the nose of the ship raised up, but for an instant only, when the machine settled down, and, after running along a hundred feet, stopped.

The agitated children pressed about, and the lieutenant tried in vain to keep them off. Some more venturesome than others, after seeing Ralph and Alfred, began to question them. To the relief of the boys they learned that the French out-posts were less than a mile distant.

"Let us make the repairs as rapidly as possible," said the lieutenant.

An examination showed that not only was the control wire cut in two places, but the vertical plane had its pivot shot away, thus accounting for the peculiar action of the lever, which seemed to jam whenever an attempt was made to turn it to the right. Ralph did not know this, while seated astride the body and manipulating the plane, and it was obvious that even though he had succeeded in splicing the wire, it would have been impossible, with the rudder in that condition, to turn by means of the wire controls.

Assisted by the machinist from the garage belonging to the owner of the school, they completed the repairs in an hour, and, hungry though they were, they again went aloft and sailed for their camp, which was reached after an absence of three hours.

They thus had less than a hour to get a hurried meal and prepare to line up with the squadron, to carry out the orders for the movement to the north. They were now going to that section of the fighting line in France where the most intense struggles up to that time had taken place, and where, ever since the opening of the conflict the most stupendous operations were being carried out to gain the mastery.

Imagine, if you can, the sight that met their gaze, as they took their place on the extreme right of the three squadrons, which were about to launch on this memorable occasion. They were about twenty miles south of the city of Verdun. The extreme northern aviation base was not more than eight miles southwest of the city, located on a level plain east of the forest of Argonne, and close to the Aire river, a tributary of the Aisne.

The trip was a short one, as the actual flying distance was less than fifteen miles. Long before they reached the scene of the great camp, they could see the thousands of vehicles, and the hundreds of thousands of soldiers, on the highways, in the fields, and around the villages along the two main railways which threaded their way along the wide valleys between the Meuse and the Aire.

During every mile of the trip they were under the constant vigilance of the officers, who moved them into echelon, formed them into squares, or caused them to trail in columns of two or three, the object being to accustom the pilots to obey and execute signals while in flight.

CHAPTER XI

A FIGHT AND A LANDING IN BELGIUM

The day following their arrival at the field base, as it was called, they found a wonderful change in the order and arrangement of the place. Everything was done in the most systematic way. So many machines, from each squadron, were told off each morning for certain duties. Those duties were as follows: First, scouting. This meant ascertaining where the enemy was most active; where the batteries were located; noting the movement of troops, and their general character.

Scouts generally operate in pairs, for if it is impossible to signal back from the ships, one continues the work while the other makes a signaling report from such point or points in the rear as will make the information useful.

The next duty is to protect the scouts from interference. This work is carried on by the large ships, which are usually provided with rapid fire guns. They need not, necessarily, be speedy, for they are to keep in touch with the speedy scout ships, the latter of which sail around over a small area so the observations can be carried on as leisurely as possible.

Third come the bomb-throwers, usually heavy-powered machines, generally not armed, as all the carrying power is devoted to the transportation of bombs. These are also guarded by the heavily armed machines. Sometimes, as in the case of the Farman machine, which the lieutenant used, they were used for scouting, and were also serviceable for fighting purposes.

In the early period of the war there were not many pilots capable of doing the duty required in all branches of the service. It was frequently the case that the aviator would command a ship with a gun on it and do double duty, acting as scout, or he would chase and fight an enemy, manipulating the gun while manoeuvering the machine. It was the sort of duty in which Lieutenant Guyon was engaged at the time he was promoted to the command, and supplied with the new type of machine.

Naturally, as commander of the squadron, he was at liberty to take any one he desired in his flights, and as he had a real affection for the boys, he took delight in having them accompany him on many of his exploits. It was the custom for the lieutenant to entrust the piloting of the machine to one of the boys, while he acted as a scout. Frequently Ralph would perform this duty, while Alfred, with his camera engaged, under the direction of the lieutenant, taking such photos as were deemed necessary to supplement the Department maps.

Thus over a month was spent in scouting duty, and, as the weather became somewhat chilly, especially in the evenings, they never went aloft without being well muffled up. One morning the lieutenant called out to the boys that they were likely to have a busy day before them, as the weather was unusually mild for the season.

When they arrived at the hangar the machine was already out of the shed, and the lieutenant was busy with the charts in consultation with the officer of the day. Evidently something unusual was afoot, for they waited more than an hour before the lieutenant re-appeared.

"You might wrap up well," he said. "I have ordered a good luncheon, as we shall have a good long scouting area to cover."

"Which way are we going?" asked Ralph.

"Directly across the city, and then to the east. There is some unusually active business going on between this and Metz."

"Think I had better load up the camera pretty well, even though it is a little misty," said Alfred.

"By all means," responded the lieutenant.

It was eleven o'clock before all was ready, when the lieutenant, addressing Ralph, said: "After we pass over Verdun, going east, we cross what is called the La Pietrie forests. The principal towns we shall visit are Conflans and Briey, both within the German lines. Through those towns are the principal railway lines which supply the enemy forces to the west with provisions and ammunition. We have eight bombs aboard to be used at convenient points. After lightening up the machine by disposing of them we may make a visit to Longwy, a town twenty-two miles north of Verdun. We ought to have good maps of the railroad sections over there."

As they arose the weather was somewhat hazy, so it was difficult to make observations at high altitudes. They, therefore, ascended at available points, and took a number of snapshots. To the left the Meuse river, and the edge of the forest beyond were distinctly visible, although they were then registering an altitude of more than 5,000 feet, and were five miles east of the river. To the east was an impenetrable haze, so the lieutenant directed the machine toward the river, and soon the German encampment and lines were visible through Barencourt.

All were on the alert to notice signs of the enemy's machines, for they were now in such a position that the Germans would be most likely to observe them, but there was not an indication that they would be molested. They then turned the machine to the northeast where a bridge was visible in the distance, and the lieutenant shouted through the tube:

"Make for the first bridge; follow the track on this side for a quarter of a mile, so as to give me a chance to aim. Then take the second bridge to the north further on, and in doing so pass the factory beyond."

"I understand," said Ralph.

The track was reached, and directions followed. Long before they were over the bridge the lieutenant pushed down the lever which released a bomb, which could plainly be seen at first, but they soon lost sight of the flying missile. A moment later the second bomb was released. How long it seemed for even the first bomb to reach the earth! As they were directly over the bridge an explosion was plainly visible. The first bomb had missed the bridge, but before they had time to comment on it the second one burst at the end of the bridge, and one of the spans went down.

The factory was now in view. "Go down lower," shouted the lieutenant.

Alfred nudged the lieutenant, and pointed to the north. "That looks like an airship," he said.

"So it is," replied the lieutenant, after a hasty glance. "But we must attend to this little business first," he continued, as his foot was extended down to the bomb dropper.

"You have hit it!" shouted Alfred in glee. "Now for the other bridge."

They were not as successful with the last structure, although three bombs were expended on it.

"Now, where is the flyer you saw?" asked the lieutenant.

"It went easy just before we reached the second bridge," said Alfred. "I don't see it now."

"Then I suppose we shall have to go to Longwy to find where it is," said the lieutenant. "Can you see the city beyond?" he continued, pointing to the north. "Go to the left of the city," he said through the tube.

"Why did you tell him to go to the left?" asked Alfred.

"In that way we can avoid the long range aircraft guns, which we know are mounted in the forts to the east of the town," was the reply.

They were soon on the northern side of the town, and in looking south they were surprised to see two machines, one making for the east and the other seeming to fly directly toward them.

"That fellow will be a little surprised when he finds what he has to deal with," said the lieutenant with a chuckle.

"It's a Fokker, isn't it?" shouted Ralph through the tube.

"Quite right; when I give the signal turn to the left, and describe a sharp circle. I'll fool him," said the lieutenant.

The signal came; the machine veered around just as the Fokker came plainly into sight. As the turn was made the lieutenant turned the machine gun to the other side, and when the sight was cleared past the wings he gave the first turn of the crank to the gun.

There was a hum and a succession of cracks, which seemed to surprise the man in the Fokker. He evidently thought that the French machine was trying to get away, or it never would have ventured so close.

"The other machine is coming!" cried Alfred.

"Here is where we can get in the fun," said the lieutenant. "Make a straight line for the one coming up in the east. Go on until I signal."