I. Plight of a Commander-in-Chief without an aeroplane corps—The work of cavalry reconnaissance.

What can be achieved by aeroplane reconnaissance, when skilfully carried out, and conducted upon an adequate scale, it will be the purpose of this section of our book to show.

In order to appreciate the services which an efficient air-corps will be able to render, the position of a Commander-in-Chief who has no aeroplanes to help him should first be understood.

In modern warfare, operations are extended over a very wide area. Sometimes, for example, a fighting line will stretch over a frontage of many miles. This makes it increasingly difficult for a Commander-in-Chief to obtain precise and speedy information concerning the movements of his enemy.

Cavalry scouts are, of course, sent out. They move cautiously forward, until they come into contact with the outposts which the enemy has thrown forward with the deliberate intention of concealing his intentions. The cavalry scouts are able to report the position of these outposts; but as to what general strategic movement is taking place behind this screen they can, as a rule, provide only meagre information, if any at all.

How difficult it is to glean anything like reliable news of an enemy's movements has been indicated by that great military genius, Napoleon. Dealing with this very question, and clearly emphasising the need for such a scouting medium as the aeroplane, he wrote:—

"Nothing is more contradictory, nothing is more bewildering, than the multitude reports of spies, or of officers sent out to reconnoitre; some locate army corps where they have seen only detachments; others see only detachments where they ought to have seen army corps.

"Often they have not themselves seen the facts they report, and they have only gathered the hearsay evidence of alarmed, surprised, or bewildered people. ... If a former preoccupation exists, if there is a tendency to believe that the enemy will come from one direction rather than from another, the gathered evidence is interpreted in one sense, however little it lends itself to being so interpreted. It is thus that great mistakes are made, which are sometimes the ruin of armies and of Empires."

Nothing could more definitely indicate the importance of accurate reconnoitring than the emphatic statement of this great soldier. Napoleon recognised that reliable information, concerning the doings of his antagonists, was all-important. A misunderstanding of some scouting report was, he knew, sufficient to lose the Commander-in-Chief a great action.

In any battle a Commander seeks, as has been truly said, to see what is going on "upon the other side of the hill."

The two armies are spread out, approaching each other. Each Commander has thrown forward a screen of men. These act, so to speak, as "feelers," seeking to come into touch with the enemy. Behind this screen of outposts comes the real strength of the army. Neither Commander knows how, when, or at what point, his opponent will develop his main attack. So they grope towards each other, any authentic news of a definite movement of troops being eagerly awaited.

If, as the result of any information brought him, one Commander-in-Chief can anticipate his opponent's chief move, he may—by that stroke alone—succeed in winning the battle which ensues.

Thus it is that a Commander-in-Chief sits at his Headquarters, with maps in front of him, asking himself one vital question: "At what point, behind the wide-flung screen of his outposts, is my enemy developing his main attack?"

The cavalry scouts, and the scouts on foot, do their work as best they can. They strive, as far as is practicable, to pierce the barrier of men which the enemy has thrown forward.

The task of these scouts is dangerous; it is laborious; and it is slow. It is also haphazard. But, from the fragmentary news that is brought back to him, a Commander-in-Chief has to act as best he can.

Some of his scouts succeed; others return with nothing at all. There are serious gaps in the intelligence; much of it may be contradictory. Yet upon such intelligence as this a Commander-in-Chief has acted in the past, and will have to act in the future, unless he has the aeroplane scout placed at his disposal.

II. Work of a squadron of air-scouts described—Tasks of the pilot and observer—Combined reconnaissance by many machines—Effect of aeroplanes upon tactics.

Having indicated the difficulties of the Commander-in-Chief, who has no aeroplane service at his disposal, it is now legitimate to show what can be accomplished with the aid of this new "arm."

We will imagine, for the sake of argument, that an action is imminent, and that the Commander-in-Chief is anxious to know, without delay, from what direction he may expect the enemy to mass his troops for a main attack. So he calls into consultation the Commander of the aeroplane depot. This depot—as has been explained in a previous section—will probably be established at a suitable point near the main body of the troops, and will be maintained at the spot chosen, until a move on the part of the army necessitates a change of quarters.

To the Commander of the aeroplane depot the Commander-in-Chief will explain the points, in regard to the general plan of campaign, upon which he requires enlightenment.

The Commander of the aeroplanes will make a note of what the Commander-in-Chief desires; then he will return to the aeroplane camp, and get to work. It is probable, in the ordinary course of affairs, that organised reconnoitring flights will be made, in wartime, either in the early hours of the morning, or during the evening. This will suit the convenience of the airmen by giving them the best weather conditions to work in; and it will also be satisfactory for the Commander-in-Chief to know at the beginning, and again at the end of a day's fighting, what the dispositions of his enemy are.

In the French manoeuvres, and also in other experiments made, it has been shown that information, concerning an enemy's movements, is generally required in the morning and in the evening; and this applies, particularly, to news gleaned in the early morning, soon after it is light. It is then, before the movements of the day, that an enemy's dispositions may best be noted.

A good deal of interest has been aroused, lately, in the suggestion that, in war-time, machines would be required to reconnoitre at night. It has been pointed out, in this connection, that large movements of troops are often made under cover of darkness.

That night reconnoitring is practical there is no doubt. How much an observer would be able to report, without the use of a searchlight, experience must prove. There seems little doubt but that an air-scout could descend low enough, at night, to detect the movements of large bodies of men.

When he has returned to the aeroplane camp, after his consultation with the Commander-in-Chief, the officer who is in charge of the aviation depot will seek an interview with the officer who is directly in control of the military pilots and observers. Maps will be consulted, and a general plan of reconnoitring drawn up; and, at this stage of the proceedings, the time will come to decide how many machines are to be sent out upon the scouting expedition.

This decision will be governed, very largely, by the extent of the area to be traversed, and also by the urgency of the mission. Although all news obtained will naturally be needed at Headquarters as quickly as possible, there will be occasions when the need for haste is very great. In such instances, more machines will be sent out than at ordinary times.

If he has a complete and rapid reconnaissance of an enemy's position to make, covering the entire area of operations, and not any one section of the battle-front, the Commander of aeroplanes will probably order a large number of machines to go upon the trip.

The value of numbers is self-evident. One machine, acting upon instructions, can be piloted over a narrow and previously-indicated route. It reports all that is seen, but its observations are necessarily restricted to what lies in its path.

It would be impossible, with one machine making one flight, to obtain anything like a comprehensive report as to an enemy's doings—at least not in reasonable time.

This is why, when a large area has to be covered, the Commander of aeroplanes will order out a regular squadron of machines. After a conversation with his immediate superior, the officer who is in charge of the airmen and observers will discuss with them the area which each machine shall cover.

Again maps will be consulted, and aerial routes will be laid down. It will be the aim of the officer instructing the airmen to spread out his scouts so as to present a complete report, when the reconnaissance is effected.

When the whole of the ground to be reconnoitred has thus been marked out upon the maps, each observer—who will be equipped with his own personal map of the fighting area—will be instructed as to the course he shall steer. He will duly note this, and return to his machine.

Whereupon, the pilots will soar into the air from their camp, and speed away upon their missions. The pilot of the aeroplane will be concerned with nothing save the control of his machine. He will not need to trouble himself about the route taken, or about what is seen below.

This work will fall upon the observer, who will be placed in the machine with an uninterrupted view of the country below him, and who will instruct the pilot as to the course he shall steer, and the elevation he shall maintain.

The observer, indeed, will be in charge of the aeroplane. Upon him will rest the responsibility of the success of the expedition, from the point of view of the information to be obtained. But the work of the pilot will be important, also. Upon his skill, in manipulating the machine, will depend the carrying out of the flight, and the safe return of the aeroplane to Headquarters.

Thus the fleet of air-scouts will start upon their errand of observation. Each machine will mount steadily, until an altitude, under ordinary conditions, of between 3000 and 4000 feet has been reached. Then, at this height, they will sweep out over the enemy's lines. The altitude mentioned is generally regarded as a good height for reconnoitring work because it permits the observer a fairly-detailed view of the ground below, and places him, also, at what is considered a safe elevation, so far as artillery fire is concerned. The important question of the vulnerability of aircraft, in regard to artillery fire, will be dealt with fully in a later section.

As the reconnoitring machine moves out over the enemy, the pilot will be busy with the control of his machine. If the weather proves very favourable, his task will be a comparatively light one. All that he will need to do is to see that he is steering accurately upon the course laid down by the observer, and that his altitude remains at the level chosen. He will also listen attentively to the running of his engine, and occasionally note the number of revolutions it is making, as recorded by an indicator placed before him.

If a reconnoitring flight has to be undertaken in adverse conditions, say with a gusty, treacherous wind blowing, the task of the pilot will be an extremely arduous one. Apart from the difficulty of keeping his craft upon a proper course, he will be faced with the nerve-racking task of preventing it from "side-slipping," under the onslaught of vicious gusts of wind.

The "side-slip" which an aeroplane may make in a gusty wind is, indeed, a very unpleasant experience for those who are on board it. What happens is this: under the influence of a sudden gust, the machine heels over until it reaches an angle when forward motion is replaced by a swift, sickening slide sideways. A machine may "side-slip" in this fashion, for an appreciable distance, before the pilot is able to regain control of it.

An example may be cited of an airman who slid down from an altitude of more than 800 feet, until he was within a couple of hundred feet of the ground. There is only one thing to do when a machine begins to "side-slip" in this way. The pilot must alter the angle of his elevating planes, so that the aeroplane dives forward as well as slips sideways. This dive adds to the machine's speed, and so checks the sideway fall; and, if his altitude is sufficient, the airman is able to regain control of his machine, and bring it back again upon an even keel, before there is danger of contact with the ground.

In bad weather, as may be imagined, a reconnoitring trip may be a serious ordeal for the man at the levers. The responsibility for undertaking a flight, in unsuitable weather conditions, will fall upon the officer in command of the aviation depot. If, for example, the wind is too high for flying, it will be his duty to tell the Commander-in-Chief so, and delay the intended reconnaissance until conditions improve.

The work of the pilot of the aeroplane, during a reconnoitring flight, has only been described so far; now we may deal with the task of the observer. He will, probably, have a busier time than the man at the levers. From the moment of leaving the ground, until the flight is finished, he will need to be on the alert.

As the aeroplane approaches the enemy's lines, he will pore over the map fixed in a frame before him. In addition to this map, he will be provided with pencil and notebook.

Thus, when any portion of the enemy's troops appear below him, his task will be perfectly clear.

He will first need to identify them. That is to say, he must be able to determine whether he is looking at infantry, cavalry, or artillery; and then he must be able to decide as to the strength of the forces that are in view.

These points determined, he will turn again to his map, so as to make sure of the actual point, on the battle line, where the troops he sees are stationed. This done, he will make notes in his book.

And so, throughout the flight, will the observation officer be busy, peering downwards; consulting his map; afterwards scribbling hastily in his notebook. If he is not quite sure what anything is that he sees below him, he will ask the pilot to circle back, so that he can make another inspection.

If the weather is perfectly clear, he may be able to instruct the airman to soar higher, and so be safer from any gun-fire from below. On the other hand, if the morning or evening is misty, he may have to take the risk of descending lower.

Each unit on the squadron of observing aeroplanes will be carrying out the same routine. Wide-spread, the air-scouts will sweep over the enemy's position. In an hour, each air-scout will be able to traverse a distance of more than fifty miles, and nothing of importance below him should pass undetected.

In a little more than an hour, from the time of their starting away, the squadron of machines should be returning to their camp. One by one they will come gliding down, and the observation officer in each machine will present a written report to his immediate chief. This officer, when all these reports are in his possession, will seek the Commander of the aviation depot. These two officers will speedily sift out the information brought in by air-scouts, and prepare, for the consideration of the Commander-in-Chief, a summary of the whole reconnaissance.

This the Commander of aeroplanes will take with him to Headquarters, and the Commander-in-Chief, with the members of his staff, will bend over their maps, tracing the enemy's dispositions, noting his weak points, and also the positions where he may be in force.

In regard to observing the actual movements of troops, as apart from the positions of stationary forces, the work of the war aeroplane should be wonderfully effective. An air-scout may, for example, report that a section of the enemy is on the march between two points at a given time. This news may be considered, by the Commander-in-Chief, to have a very important bearing upon the development of the enemy's plan of campaign. Is this body of troops still moving in the same direction, say an hour later? This may, quite likely, be the question upon which the Commander-in-Chief may want information.

Upon hearing this, the Commander of aeroplanes will soon have two or three scouting machines on the move. There will be no difficulty about such individual work as this; and very soon the Commander-in-Chief should be supplied with the news that he requires.

Thus it is possible to outline, in a general way, the reconnoitring work of the war aeroplane. It is not necessary to emphasise again the value of information which can be borne so quickly to a Commander-in-Chief; the importance of the news which will be gleaned by the air-scouts is, indeed, self-evident.

As the result of an aerial reconnaissance by many machines, well-organised and successfully carried out, the Commander-in-Chief should be supplied with information which could not possibly be acquired in any other way, and which should tell him where the enemy was, and what they were doing, only an hour before the news is put before him.

On such information, also, he can act with confidence. He need not hesitate, questioning its authenticity. On the maps before him, set forth in a manner beyond dispute, he will have the position of his foe, and the direction in which the chief bodies of troops are being moved.

Nor is this all that the aeroplane can do, as has been shown. If a Commander-in-Chief is in doubt about any movement of the enemy, during the course of an action, he still has the aeroplane at his immediate service.

There is no reason, indeed, why constant reconnaissances should not be made during the course of a battle. Suppose, for example, that a heavy attack has been made upon the enemy. It is sought to know whether such onslaught has had its full effect. Is the enemy falling back? This may become a question of great urgency, as it may govern a Commander-in-Chiefs next offensive move. Here is a task in which the air-scout can reveal his worth.

Rising high, and flying over the enemy, he should be able to determine whether a retreat has begun, and should bring back this information to Headquarters with a minimum of delay. A definite instance of the use of the aeroplane in this connection was, it may be remembered, given in the French manoeuvres in Picardy, when Lieutenant Sido was able to inform his Headquarters that the enemy was in retreat, after an important action.

If his aeroplane service is efficient, and there is no delay in obtaining news, a Commander-in-Chief should be receiving constant intelligence, concerning the movements of the enemy, during the progress of a battle. It may be extremely important, for example, to know that the enemy is bringing up batteries to a certain point; or that a hill, or other point of vantage, is to be abandoned. From first to last, indeed, the aeroplane should be of the greatest use.

But, as has been shown before, it will not be so much a case of the number of aeroplanes used, as of the organisation behind them. In this lies the crux of the situation. Unless pilots and observers are absolutely competent, and ready for their work, the results obtained cannot be satisfactory.

The influence of the aeroplane scout upon military tactics will, undoubtedly, be marked. The German school, for example, advocates a strong, determined advance—not caring so much what the precise dispositions of an enemy are, but seeking to envelop him, and deliver one quick and crushing blow.

French military tactics, on the other hand, are more strategical—more prone to play a waiting, watching game, and make a master-move after the battle scheme has, to a certain extent, revealed itself.

What has been called "the fog of war"—that is to say, the meagre information regarding an enemy's movements, which is all that is available if aeroplanes are not used—suits the German method of blunt, dogged, hit-or-miss advance. Lack of information is not advantageous, on the other hand, to the carefully thought-out French strategy.

What the advent of the air-scout does is to help the Commander-in-Chief, who is able to make subtle, deeply-planned moves, in which precise information is essential, and to discount a blind, crushing use of numbers.

III. Other uses of the war aeroplane—Surveying—Dispatch-carrying—Directing gun-fire—Transport of staff officers.

The duties so far mentioned do not, by any means, exhaust the possibilities of the war aeroplane. So far, only military reconnaissance has been touched upon. This work is, of course, of outstanding importance; but an air-corps could, during a campaign, be put to many other tasks, all of them of genuine utility.

Take, for example, the work of discovering the nature of the country over which an army is about to operate. This is a task which is extremely important. But, hitherto, the process of obtaining such information has been painfully slow—painfully slow, that is, when compared with the way the aeroplane will be able to carry out the work.

Here, indeed, will be an ideal opportunity for a long-distance flight. In a three-hour, non-stop journey, a machine should be able to survey at least 150 miles of country, and return with reports of the utmost value.

How important this aerial survey-work will be is instanced by Major J. N. C. Kennedy, who, from his experience in the South African war, states that such disasters as Spion Kop could not have happened, if there had been aeroplanes to fly over and observe the country beforehand.

Here, then, is another practical use for the aeroplane. A squadron of machines, flying ahead of an army on the march, will be able to return with accurate news as to the position of roads, railways, rivers, and bridges. Such information, received in good time, may prove of exceptional value to a Commander-in-Chief.

Apart from general survey work, also, the air-corps will be able to execute highly-important orders in locating the position of an enemy's supply trains, magazines, and depots.

Thus it can be seen that there will be practically constant use for war aeroplanes during a campaign—apart from their potentialities as weapons of destruction, concerning which notes will be written later.

So highly does he rate the work of aircraft in wartime, for reconnoitring purposes, that the director of the military aviation service of the French army has declared: "Aeroplanes, carrying a steersman, observer, and combatant, will eventually supersede cavalry for scouting purposes."

In this regard, it is interesting to note the opinion of a famous German military expert, who says:—

"They (aeroplanes) will collect much information which would never be accessible to cavalry, and, above all, they will do it over long distances, and in a much shorter time. It is a defect of cavalry reconnaissance that the knowledge which it yields has necessarily, in the great majority of eases, been long overtaken by events. No small gifts, on the part of the General, are necessary to infer, from what was ascertained many hours previously, what is actually the existing situation. The possibilities of error are very great."

Here is another striking tribute to the value of the war aeroplane. What this German expert was particularly impressed by, after observing a series of tests of aeroplanes for reconnoitring, was their wonderful speed, as compared with any other means of obtaining information.

The point he makes, in this connection, is highly important. Not only will the aeroplane scout bring back news which it would be impossible to obtain by the use of cavalry, but he will place this news in the hands of a Commander-in-Chief while it is fresh, and of the fullest importance, and not many hours old—as the intelligence brought in by other methods of reconnaissance generally is.

Another extremely useful function of the aeroplane, during a campaign, must not be forgotten. This is its use as a dispatch-carrier. In this regard, a light, swift machine will be found of utility. No ordinary obstacle will hamper it. The fact that the country is mountainous, or that there are awkward rivers to negotiate, present serious problems for the dispatch-rider, who sets out to carry a communication from point to point on horseback. In many cases, indeed, it becomes impossible to send a dispatch across country.

But the aeroplane dispatch-carrier will think nothing of such difficulties as these. Over precipitous country, and across mountains, he will fly without hindrance; and he will be faced with no problems concerning the fording of rivers. As straight as an arrow, from point to point, he will carry his message, and at a pace in excess of that of the express train.

The fact that skirmishing parties of the enemy are dotted about, between his starting-point and his objective, will not perplex him either, although it would prove a serious embarrassment to the dispatch-rider who used the land when in transit.

Instances of the practical value of dispatch-carrying, in time of war, are readily forthcoming. A distinguished cavalry-officer, Colonel Grantham, supplies one, for instance. In the Chinese war, he recalls the plight of two columns which were advancing, about twenty miles apart, to deliver a combined attack. The country dividing them was mountainous; parties of the enemy were also moving about on it. The result was that, for several days, no message could be got through. This lack of communication made the scheme of a joint advance very difficult to carry out. Had an aeroplane dispatch-carrier been available, in such circumstances as these, he would have linked up the two columns in a twenty-minute flight, irrespective of all that lay below him.

It is, of course, frequently necessary, during the progress of a battle, for Generals commanding various sections of an army to report to the Commander-in-Chief. Here the dispatch-carrying aeroplane, on account of its speed, will be of the greatest value.

What can be done, in the way of long-distance dispatch-carrying, has been demonstrated most effectually by Captain Bellenger, a well-known French military airman. This officer, while stationed at the Vincennes air-depot, received instructions to carry a dispatch, as quickly as possible, to the military flying school at Pau. This represented a distance of 450 miles. Starting early one morning, Captain Bellenger reached Pau in seven hours sixteen minutes of actual flying. While en route he made three halts to replenish his petrol tank.

Recent tests in France show that quickly-assembled, single-seated monoplanes will be extremely useful, in actual military operations, in co-operating with artillery, by giving aerial directions as to gun-fire.

Upon occasions when the effect of long-distance fire is unknown to the gunner, an aerial observer, ascending to an altitude of several thousand feet, will be able to detect what mischief the shells are doing, and suggest—either by wireless telegraphy or by messages dropped from his machine—corrections in the gunner's aim.

Another field of practical utility for the aeroplane, during an action, lies in the quick transport, from place to place, of staff officers. Horses, motor-cars, and motor-cycles have, hitherto, been employed for this purpose. But the aeroplane is infinitely their superior in the matter of speed.

Roads may be blocked with troops, or transport waggons, thereby holding up, temporarily, the passage of any motor-cars or motor-cycles. No such hindrances affect the aeroplane. With such reliable passenger-carrying machines as are now available, staff officers will be able to flit from point to point on a battlefield, with a minimum of delay. This will prove an extremely valuable addition to what may be termed the conveniences of war.

It is legitimate, at this juncture, having illustrated the uses of an aeroplane in time of war, to picture, briefly, the contrast between two Commanders-in-Chief, one of them possessing an up-to-date fleet of war aeroplanes, and the other without any such aid. Prior to an action, the one who has an aeroplane corps sends out his machines upon a general reconnaissance. As a result he is, in an hour or so, in possession of all the information he requires concerning the enemy. He is able to calculate where his antagonist's main blow is to be struck; and he is also able to estimate the weak points in his opponent's fighting line.

The Commander who is without aeroplanes sends out his cavalry scouts, in the time-honoured fashion, and relies upon news from outposts. What information he thus obtains is bound to be many hours older than that, concerning his own movements, which is in the possession of the enemy. Furthermore, it leaves many questions of urgency altogether unanswered. But, unsatisfactory though his knowledge of his opponent's intentions is, the Commander has to grope forward. A certain blind doggedness actuates him; it is a case, more or less, of hit-or-miss.

Now, were his opponent in a similarly fumbling state of mind, it would not matter so much. But, thanks to his aeroplanes, Commander No. 1 has his opponent's dispositions and movements carefully marked upon his maps.

Thus the two armies come into conflict. One Commander-in-Chief knows everything; the other knows practically nothing. What is the result likely to be? One strikes swiftly and surely, aware of the precise strength opposed to him. The other fumbles blindly in the dark.