Then the venturesome airman cannot neglect another factor which is adverse to his success. Hostile airmen lie in wait, and a fleet of aeroplanes is kept ready for instant service. They permit the invader to penetrate well into their territory and then ascend behind him to cut off his retreat. True, the invader has the advantage of being on the wing, while the ether is wide and deep, without any defined channels of communication. But nine times out of ten the adventurous scout is trapped. His chances of escape are slender, because his antagonists dispose themselves strategically in the air. The invader outpaces one, but in so doing comes within range of another. He is so hara.s.sed that he either has to give fight, or, finding his retreat hopelessly cut off, he makes a determined dash, trusting to his high speed to carry him to safety. In these driving tactics the French and British airmen have proved themselves adepts, more particularly the latter, as the chase appeals to their sporting instincts. There is nothing so exhilarating as a quarry who displays a determination to run the gauntlet.

The roving Teuton scout was considerably in evidence in the early days of the war, but two or three weeks' experience emphasised the sad fact that, in aerial strategy, he was hopelessly outmatched by his opponents.

His advantage of speed was nullified by the superior tactical and strategical ac.u.men of his antagonists, the result being that the German airman, who has merely been trained along certain lines, who is in many cases nothing more than a cog-wheel in a machine, and who is proverbially slow-witted, has concluded that he is no match for the airmen of the Allies. He found from bitter experience that nothing afforded the Anglo-French military aviators such keen delight as to lie in wait for a "rover," and then to swoop into the air to round him up.

The proportion of these individual scouts who were either brought down, or only just succeeded in reaching safety within their own lines, and who were able to exhibit serious wounds as evidence of the severity of the aerial tussle, or the narrowness of the escape, has unnerved the Teuton airmen as a body to a very considerable extent. Often, even when an aeroplane descended within the German lines, it was found that the roving airman had paid the penalty for his rashness with his life, so that his journey had proved in vain, because all the intelligence he had gained had died with him, or, if committed to paper, was so unintelligible as to prove useless.

It was the success of the British airmen in this particular field of duty which was responsible for the momentous declaration in Field-Marshal Sir John French's famous despatch:--"The British Flying Corps has succeeded in establishing an individual ascendancy, which is as serviceable to us as it is damaging to the enemy.... The enemy have been less enterprising in their flights. Something in the direction of the mastery of the air has already been gained."

The methods of the British airmen are in vivid contrast to the practice of the venturesome Teuton aerial rovers described above. While individual flights are undertaken they are not of unknown duration or mileage. The man is given a definite duty to perform and he ascends merely to fulfil it, returning with the information at the earliest possible moment. It is aerial scouting with a method. The intelligence is required and obtained for a specific purpose, to govern a contemplated move in the grim game of war.

Even then the flight is often undertaken by two or more airmen for the purpose of checking and counterchecking information gained, or to ensure such data being brought back to headquarters, since it is quite possible that one of the party may fall a victim to hostile fire. By operating upon these lines there is very little likelihood of the mission proving a complete failure. Even when raids upon certain places such as Dusseldorf, Friedrichshafen or Cuxhaven are planned, complete dependence is not placed on one individual. The machine is accompanied, so that the possibility of the appointed task being consummated is transformed almost into a certainty.

The French flying men work upon broadly similar lines. Their fleet is divided into small squadrons each numbering four, six, or more machines, according to the nature of the contemplated task. Each airman is given an area of territory which is to be reconnoitred thoroughly. In this way perhaps one hundred or more miles of the enemy's front are searched for information at one and the same time. The units of the squadron start out, each taking the appointed direction according to the preconceived plan, and each steering by the aid of compa.s.s and map. They are urged to complete the work with all speed and to return to a secret rendezvous.

Later the air is alive with the whirring of motors. The machines are coming back and all converging to one point. They vol-plane to the earth and gracefully settle down within a short distance of each other at the rendezvous. The pilots collect and each relates the intelligence he has gained. The data are collated and in this manner the General Staff is able to learn exactly what is transpiring over a long stretch of the hostile lines, and a considerable distance to the rear of his advance works. Possibly five hundred square miles have been reconnoitred in this manner. Troops have been ma.s.sed here, lines of communication extend somewhere else, while convoys are moving at a third place. But all has been observed, and the commanding officer is in a position to re-arrange his forces accordingly. It is a remarkable example of method in military tactics and strategy, and conveys a striking idea of the degree to which aerial operations have been organised.

After due deliberation it is decided that the convoys shall be raided, or that ma.s.sed troops shall be thrown into confusion, if not dispersed.

The squadron is ordered to prepare for another aerial journey. The roads along which the convoys are moving are indicated upon the map, or the position of the ma.s.sed troops in bivouac is similarly shown. The airmen load their machines with a full charge of bombs. When all is ready the leader ascends, followed in rapid succession by the other units, and they whirr through the air in single file. It now becomes a grim game of follow-my-leader.

The leader detects the convoy, swoops down, suddenly launches his missiles, and re-ascends. He does not deviate a foot from his path to observe the effects of his discharge, as the succeeding aeroplane is close behind him. If the leader has missed then the next airman may correct his error. One after another the machines repeat the manoeuvre, in precisely the same manner as the units of a battleship squadron emulate the leading vessel when attacking the foe. The tactical evolutions have been laid down, and there is rigid adherence thereto, because only thereby may success be achieved. When the last war-plane has completed its work, the leader swings round and repeats the dash upon the foe. A hail of bullets may scream around the men in the air, but one and all follow faithfully in the leader's trail. One or more machines may fail in the attack, and may even meet with disaster, but nothing interferes with the movements of the squadron as a whole. It is the h.o.m.ogeneity of the attacking fleet which tells, and which undermines the moral of the enemy, even if it does not wreak decisive material devastation. The work accomplished to the best of their ability, the airmen speed back to their lines in the same formation.

At first sight reconnoitring from aloft may appear a simple operation, but a little reflection will reveal the difficulties and arduousness of the work. The observer, whether he be specially deputed, or whether the work be placed in the hand of the pilot himself--in this event the operation is rendered additionally trying, as he also has to attend to his machine must keep his eyes glued to the ground beneath and at the same time be able to read the configuration of the panorama revealed to him. He must also keep in touch with his map and compa.s.s, so as to be positive of his position and direction. He must be a first-cla.s.s judge of distances and heights.

When flying rapidly at a height of 4,000 feet or more, the country below appears as a perfect plane, or flat stretch, although as a matter of fact it may be extremely undulating. Consequently, it is by no means a simple matter to distinguish eminences and depressions, or to determine the respective and relative heights of hills.

If a rough sketch is required, the observer must be rapid in thought, quick in determination, and facile with his pencil, as the machine, no matter how it may be slowed down, is moving at a relatively high speed.

He must consult his map and compa.s.s frequently, since an airman who loses his bearings is useless to his commander-in-chief. He must have an eagle eye, so as to be able to search the country unfolded below, in order to gather all the information which is likely to be of value to his superior officers. He must be able to judge accurately the numbers of troops arrayed beneath him, the lines of the defensive works, to distinguish the defended from the dummy lines which are thrown up to baffle him, and to detect instantly the movement of the troops and the direction, as well as the roads, along which they are proceeding.

Reserves and their complement, artillery, railway-lines, roads, and bridges, if any, over streams and railways must be noted--in short he must obtain an eye photograph of the country he observes and grasp exactly what is happening there. In winter, with the thermometer well down, a blood-freezing wind blowing, wreaths of clouds drifting below and obscuring vision for minutes at a time, the rain possibly pelting down as if presaging a second deluge, the plight of the vigilant human eye aloft is far from enviable.

Upon the return of the machine to its base, the report must be prepared without delay. The picture recorded by the eye has to be set down clearly and intelligibly with the utmost speed. The requisite indications must be made accurately upon the map. Nothing of importance must be omitted: the most trivial detail is often of vital importance.

A facile pencil is of inestimable value in such operations. While aloft the observer does not trust to his memory or his eye picture, but commits the essential factors to paper in the form of a code, or what may perhaps be described more accurately as a shorthand pictorial interpretation of the things he has witnessed. To the man in the street such a record would be unintelligible, but it is pregnant with meaning, and when worked out for the guidance of the superior officers is a ma.s.s of invaluable detail.

At times it so happens that the airman has not been able to complete his duty within the time antic.i.p.ated by those below. But he has gathered certain information which he wishes to communicate without coming to earth. Such data may be dropped from the clouds in the form of maps or messages. Although wireless telegraphy is available for this purpose, it suffers from certain drawbacks. If the enemy possesses an equipment which is within range of that of the air-craft and the force to which it belongs, communications may be nullified by the enemy throwing out a continuous stream of useless signals which "jamb" the intelligence of their opponents.

If a message--written in code--or a map is to be dropped from aloft it is enclosed within a special metallic cylinder, fitted with a vane tail to ensure direction of flight when launched, and with a detonating head.

This is dropped overboard. When it strikes the ground the detonator fires a charge which emits a report without damaging the message container, and at the same time fires a combustible charge emitting considerable smoke. The noise attracts anyone in the vicinity of the spot where the message has fallen, while at the same time the clouds of smoke guide one to the point and enable the cylinder to be recovered.

This device is extensively used by the German aviators, and has proved highly serviceable; a similar contrivance is adopted by French airmen.

There is one phase of aerial activity which remains to be demonstrated.

This is the utilisation of aerial craft by the defenders of a besieged position such as a ring of fortifications or fortified city. The utility of the Fourth Arm in this province has been the subject of considerable speculation. Expert opinion maintains that the advantage in this particular connection would rest with the besiegers. The latter would be able to ascertain the character of the defences and the defending gun-force, by means of the aerial scout, who would prove of inestimable value in directing the fire of the besieging forces.

On the other hand it is maintained that an aerial fleet would be useless to the beleaguered. In the first place the latter would experience grave difficulties in ascertaining the positions of the attacking and fortress-reducing artillery, inasmuch as this could be masked effectively, and it is thought that the aerial force of the besieged would be speedily reduced to impotence, since it would be subjected to an effective concentrated fire from the ring of besieging anti-aircraft guns and other weapons. In other words, the theory prevails that an aerial fleet, no matter how efficient, would be rendered ineffective for the simple reason that it would be the initial object of the besieger's attack. Possibly the stem test of experience will reveal the fallacy of these contentions as emphatically as it has disproved others. But there is one point upon which authorities are unanimous. If the artillery of the investing forces is exposed and readily distinguishable, the aerial forces of the beleaguered will bring about its speedy annihilation, as the defensive artillery will be concentrated upon that of the besiegers.

CHAPTER IX. THE AIRMAN AND ARTILLERY

There is one field in which the airman has achieved distinctive triumphs. This is in the guidance of artillery fire. The modern battle depends first and foremost upon the fierce effectiveness of big-gun a.s.sault, but to ensure this reliable direction is imperative. No force has proved so invaluable for this purpose as the man of-the-air, and consequently this is the province in which he has been exceptionally and successfully active.

It will be recalled that in the j.a.panese invest.i.ture of Port Arthur during the Russo-j.a.panese war, thousands of lives were expended upon the retention and a.s.sault of 203 Metre Hill. It was the most blood-stained spot upon the whole of the Eastern Asiatic battlefield. General Nogi threw thousands after thousands of his warriors against this rampart while the Russians defended it no less resolutely. It was captured and re-captured; in fact, the fighting round this eminence was so intense that it appeared to the outsider to be more important to both sides than even Port Arthur itself.

Yet if General Nogi had been in the possession of a single aeroplane or dirigible it is safe to a.s.sert that scarcely one hundred j.a.panese or Russian soldiers would have met their fate upon this hill. Its value to the j.a.panese lay in one sole factor. The j.a.panese heavy guns sh.e.l.ling the harbour and the fleet it contained were posted upon the further side of this eminence and the fire of these weapons was more or less haphazard. No means of directing the artillery upon the vital points were available; 203 Metre Hill interrupted the line of sight. The j.a.panese thereupon resolved to capture the hill, while the Russians, equally appreciative of the obstruction it offered to their enemy, as valiantly strove to hold it. Once the hill was captured and the fire of the j.a.panese guns could be directed, the fate of the fortress was sealed.

Similar conditions have prevailed during the present campaign, especially in the western theatre of war, where the ruggedness of the country has tended to render artillery fire ineffective and expensive unless efficiently controlled. When the German Army attacked the line of the British forces so vehemently and compelled the retreat at Mons, the devastating fire of the enemy's artillery was directed almost exclusively by their airmen, who hovered over the British lines, indicating exactly the point where gun-fire could work the maximum of havoc. The instant concentration of ma.s.sed artillery fire upon the indicated positions speedily rendered one position after another untenable.

The Germans maintained the upper hand until at last the aerial forces of the British Expeditionary Army came into action. These airmen attacked the Teuton aerial craft without the slightest hesitation, and in a short while rendered cloudland absolutely unhealthy. The sequel was interesting. As if suddenly blinded, the German artillery fire immediately deteriorated. On the other hand, the British artillery, now having the benefit of aerial guidance, was able to repay the German onslaughts with interest, and speedily compelled that elaborate digging-in of the infantry lines which has now become so characteristic of the opposing forces.

So far as the British lines are concerned the men in the trenches keep a sharp look-out for hostile aeroplanes. The moment one is observed to be advancing, all the men seclude themselves and maintain their concealment. To do otherwise is to court a raking artillery outburst.

The German aeroplane, detecting the tendency of the trenches describes in the air the location of the vulnerable spot and the precise disposition by flying immediately above the line. Twice the manoeuvre is repeated, the second movement evidently being in the character of a check upon the first observation, and in accordance with instructions, whereupon the Tommies, to quote their own words, "know they are in for it!" Ere the aeroplane has completed the second manoeuvre the German guns ring out.

The facility with which artillery fire can be concentrated through the medium of the aeroplane is amazing. In one instance, according to the story related to me by an officer, "a number of our men were resting in an open field immediately behind the second line of trenches, being in fact the reserves intended for the relief of the front lines during the following night. An aeroplane hove in sight. The men dropped their kits and got under cover in an adjacent wood. The aeroplane was flying at a great height and evidently laboured under the impression that the kits were men. Twice it flew over the field in the usual manner, and then the storm of shrapnel, 'Jack Johnsons' and other tokens from the Kaiser rained upon the confined s.p.a.ce. A round four hundred sh.e.l.ls were dropped into that field in the short period of ten minutes, and the range was so accurate that no single sh.e.l.l fell outside the s.p.a.ce. Had the men not hurried to cover not one would have been left alive to tell the tale, because every square foot of the land was searched through and through.

We laughed at the short-sightedness of the airman who had contributed to such a waste of valuable shot and sh.e.l.l, but at the same time appreciated the narrowness of our own escape."

The above instance is by no means isolated. It has happened time after time. The slightest sign of activity in a trench when a "Taube" is overhead suffices to cause the trench to be blown to fragments, and time after time the British soldiers have had to lie p.r.o.ne in their trenches and suffer partial burial as an alternative to being riddled by shrapnel.

The method of ascertaining the range of the target from the indications given by the aeroplane are of the simplest character. The German method is for the aerial craft to fly over the position, and when in vertical line therewith to discharge a handful of tinsel, which, in falling, glitters in the sunlight, or to launch a smoking missile which answers the same purpose as a projectile provided with a tracer. This smoke-ball being dropped over the position leaves a trail of black or whitish smoke according to the climatic conditions which prevail, the object being to enable the signal to be picked up with the greatest facility. The height at which the aerial craft is flying being known, a little triangulation upon the part of the observer at the firing point enables him to calculate the range and to have the guns laid accordingly.

When the aerial craft has been entrusted with the especial duty of directing artillery-fire, a system of communication between the aerial observer and the officer in charge of the artillery is established, conducted, of course, by code. In the British Army, signalling is both visual and audible. In daylight visual signalling is carried out by means of coloured flags or streamers and smoke-signals, while audible communication is effected by means of a powerful horn working upon the siren principle and similar to those used by automobiles. Both flags and sound-signals, however, are restricted owing to the comparatively short distances over which they can be read with any degree of accuracy. The smoke-signal therefore appears to be the most satisfactory and reliable, as the German airmen have proved conclusively, for the simple reason that the trail of smoke may be picked up with comparative ease, even at a distance, by means of field gla.s.ses. The tinsel too, is readily distinguishable, particularly in bright weather, for the glittering surface, catching the sun-light, acts some what in the manner of a heliograph.

The progress of the airman is followed by two officers at the base from which he started. One is equipped with the director, while the second takes the range. Directly this has been found as a result of calculation, the guns are laid ready for firing. In those cases where the enemy's artillery is concealed perhaps behind a hill, the airman is of incalculable value, inasmuch as he is able to reveal a position which otherwise would have to be found by considerable haphazard firing, and which, even if followed by a captive balloon anch.o.r.ed above the firing point, might resist correction.

The accuracy of the airman's work in communicating the range has been responsible for the high efficiency of the British and French artillery.

The latter, with the 75 millimetre quick-firing gun, is particularly adapted to following up the results of the aeroplane's reconnaissance, especially with the system of rafale fire, because the whole position can be searched through and through within a minute or two. According to information which has been given to me by our artillery officers, the British system also has proved disastrous to the enemy. The practice is to get the range as communicated by the aeroplane, to bring the artillery into position speedily, to discharge salvo after salvo with all speed for a few minutes, and then to wheel the artillery away before any hostile fire can be returned. The celerity with which the British artillery comes into, and goes out of, action has astonished even our own authorities. This mobility is of unique value: it is taking advantage of a somewhat slow-witted enemy with interest. By the time the Germans have opened fire upon the point whence the British guns were discharged, the latter have disappeared and are ready to let fly from another point, some distance away, so that the hostile fire is abortive.

Mobility of such a character is decidedly unnerving and baffling even to a quick-witted opponent.

In his search for hostile artillery the airman runs grave risks and displays remarkable resource. It is invariably decided, before he sets out, that he shall always return to a certain alt.i.tude to communicate signals. Time after time the guns of the enemy have been concealed so cunningly from aerial observation as to pa.s.s unnoticed. This trait became more p.r.o.nounced as the campaigns of the Aisne progressed.

Accordingly the airman adopts a daring procedure. He swoops down over suspicious places, where he thinks guns may be lurking, hoping that the enemy will betray its presence. The ruse is invariably successful. The airman makes a sudden dive towards the earth. The soldiers in hiding below, who have become somewhat demoralised by the accuracy of the British aerial bomb-throwers, have an attack of nerves. They open a spirited fusillade in the hope of bringing the airman to earth. But their very excitement contributes to his safety. The shots are fired without careful aim and expend themselves harmlessly. Sweeping once more upwards, the airman regains the pre-determined level, performs a certain evolution in the air which warns the observer at his base that he has made a discovery, and promptly drops his guiding signal directly over the point from which he has drawn fire.

Operations at night are conducted by means of coloured lights or an electrical searchlight system. In the former instance three lights are generally carried--white, red, and green--each of which has a distinctive meaning. If reliance is placed upon the electric light signalling lamp, then communications are in code. But night operations are somewhat difficult and extremely dangerous, except when the elements are propitious. There is the ground mist which blots everything from sight, rendering reconnaissance purely speculative. But on a clear night the airman is more likely to prove successful. He keeps a vigilant eye upon all ground-lights and by close observation is able to determine their significance. It is for this reason that no lights of any description are permitted in the advance trenches. The striking of a match may easily betray a position to the alert eye above.

So far as the British Army is concerned a complete code is in operation for communicating between aeroplanes and the ground at night. Very's lights are used for this purpose, it being possible to distinguish the respective colours at a distance of six miles and from an alt.i.tude of 2,000 feet. The lights are used both by the aeroplane and the battery of artillery.

The code is varied frequently, but the following conveys a rough idea of how communication is carried out by this means under cover of darkness.

The aeroplane has located its objective and has returned to the pre-arranged alt.i.tude. A red light is thrown by the airman. It indicates that he is directly over the enemy's position. A similarly coloured light is shown by the artillery officer, which intimates to the airman that his signal has been observed and that the range has been taken.

In observing the effects of artillery fire a code of signals is employed between the airman and the artillery officer to indicate whether the shot is "long" or "short," to the right or to the left of the mark, while others intimate whether the fuse is correctly timed or otherwise.

It is necessary to change the code fairly frequently, not only lest it should fall into the enemy's hands, but also to baffle the hostile forces; otherwise, after a little experience, the latter would be able to divine the significance of the signals, and, in antic.i.p.ation of being greeted with a warm fusillade, would complete hurried arrangements to mitigate its effects, if not to vacate the position until the bombardment had ceased.

Sufficient experience has already been gathered, however, to prove the salient fact that the airman is destined to play an important part in the direction and control of artillery-fire. Already he has been responsible for a re-arrangement of strategy and tactics. The man aloft holds such a superior position as to defy subjugation; the alternative is to render his work more difficult, if not absolutely impossible.

CHAPTER X. BOMB-THROWING FROM AIR-CRAFT

During the piping times of peace the utility of aircraft as weapons of offence was discussed freely in an academic manner. It was urged that the usefulness of such vessels in this particular field would be restricted to bomb-throwing. So far these contentions have been substantiated during the present campaign. At the same time it was averred that even as a bomb-thrower the ship of the air would prove an uncertain quant.i.ty, and that the results achieved would be quite contrary to expectations. Here again theory has been supported by practice, inasmuch as the damage wrought by bombs has been comparatively insignificant.

The Zeppelin raids upon Antwerp and Britain were a fiasco in the military sense. The damage inflicted by the bombs was not at all in proportion to the quant.i.ty of explosive used. True, in the case of Antwerp, it demoralised the civilian population somewhat effectively, which perhaps was the desired end, but the military results were nil.