The aeroplane has completely revolutionised warfare, inasmuch as it has deprived strategy of its chief weapon—surprise. As the eyes of the army the aeroplane played its most important rôle. A light and very speedy machine is the scout, and it is his duty to make reconnaissances, report upon gun emplacements, the numbers of the opposing troops, the movements of the enemy, and the disposition of his trenches. But the aeroplanes used in warfare are not all alike. The tendency is towards differentiation, and while the scout is swift and light, the battle-plane is extremely powerful and heavily armed with cannon or machine-guns, sometimes also carrying a spur for ramming enemy craft; and again there is a third type of machine armed also for defence, but adapted principally to range-finding, and fitted with signalling and photographic apparatus; it hovers continually over the enemy lines directing artillery fire. None of the offices of the aeroplane proved more valuable than that of giving the range of enemy positions to one's own artillery, and then registering the shots, marking where they fell too short, or overpassed the mark. This is one of the most dangerous as well as the most useful of the services rendered by the man-bird. It requires great nerve, judgment, and coolness on the part of the aviator, for he must hang over the enemy trenches and expose himself to the fire of their anti-aircraft guns, the efficacity of which made rapid strides as the war progressed. The German method of signalling to the opposing batteries by means of smoke bombs with different-coloured fuses was soon improved upon by the French, who used wireless telegraphy and the heliograph by day. But the rôle of the aeroplane is not confined even to these important services. It becomes at times the instrument of aerial bombardment for the destruction of fortified places, military stores, railway junctions, dirigible sheds, encampments, bridges, and roads used by the military. When war broke out, the French airmen received explicit instructions not to bombard any town for fear of inflicting harm upon civilians, but the Germans were not so scrupulous, and their defiance of the dictates of humanity forced a change in the policy of their Allies, if only in self-defence.

The aeroplane could be used also as a link for communicating with armies and their staffs, particularly in the case of a besieged army or town. And, finally, the man-bird is admirable in the capacity of aerial policeman; he can watch the clouds and he can prevent the passage of the enemy pilots. Not that it is possible to suppose that one force of aeroplanes, however numerous, can completely occupy the heavens, for the skies are broad; but bold aviators ever on the watch, patrolling the sky in constant relays (as was the case in the aerial defence of Paris against the Zeppelins), will generally succeed, whatever measures are taken against them, in overtopping the adversary; and the French aviator is remarkably good in that sort of warfare where native audacity and resource are in demand—that is why the Frenchman is so superb a performer in the air. None the less it is impossible quite to bar out the enemy. The clouds may always hide a foe; the fog is ever the possible lurking ground of the hostile airship. But although the barrage system (so successfully applied on solid earth in the tir de barrage) cannot absolutely prevent a Zeppelin attack upon a wide-spreading town, yet the aerial dam has given good results in the war of the air. The procedure is to institute a barrage of aeroplanes over against a certain locality—a certain restricted space. The enemy is marked down and prevented from passing. Undesirable visitors are invited to "move on," and they do not wait for a repetition of the request! I have heard of one hardy airman who, charged to watch the heavens against the passage of the adversary, so manoeuvred that the thick heavy clouds which hung in the sky were positively useful to him as a screen. Noting that at one point there was a clear space in the dense curtain of fog, he placed himself there and watched as a look-out might in the embrasure of a fort. None came to challenge his vigilance.

Again the barrage tactics are extremely useful in the prevention of secrets being divulged to the enemy. Certain important movements, such as the moving up of reinforcements, are taking place in a certain part of the line, and to keep the enemy from knowledge of the fact squadrillas of battle-planes are sent up to bar the way to the enemy scouts, and nothing can penetrate the screen of the avions. Thus it has so happened that, thanks to the barrage system, the enemy has been without definite news of the Allies' movements during twenty-four hours. But let it be remembered that the aerial dam implies the mastery of the air, as important to the Allies as the mastery of the seas: indeed, one could establish a very close analogy between the two. The mastery of the air—the complete mastery—would have meant the finish of the war, the absolute victory for that side which possessed it. And the aerial fleet must consist of aeroplanes, not Zeppelins. For after all the Zeppelins failed miserably either in their bombardment of England or their assault upon French towns. True they have taken toll of a certain number of innocent lives in England, but an infinitesimal number in comparison with the holocaust caused by a terrestrial bombardment. Cumbersome, unwieldy, unable to operate except in a fog, the Zeppelin was comparatively ineffectual as an engine of war, and would not have been employed by the Germans except to prevent the public exposure of a mistaken policy. Six aeroplanes could effect more damage than one Zeppelin, whose radius of action is circumscribed by the fact that it has to carry vast weight for a long journey, that it is expensive to build, and consumes immense quantities of fuel en route; that it is almost as dangerous to itself as to the enemy on account of its vulnerability from cannon and from high winds, and moreover it is constantly exposed to attack from the upper strata of air by the aeroplane which swoops down upon it with the speed of the eagle, and against which the Zeppelin has no defence. No, it is the aeroplane that has come to stay, and a very prominent airman—a man who bears a household name in aeronautics—declared to me that the side which could furnish ten thousand aeroplanes with the airmen to mount them would win the war. For if aerial bombardment had, up to that moment, taken very little place in the hostilities it was because it was on so small a scale. Very little effect was to be obtained by sending half a dozen apparati over a town—it is true that in some of the French raids over German towns there were as many as thirty machines employed, but this was the great exception. It is easy to conjure up the effect of a gigantic bombardment—a shower of metal from the sky—rained everywhere upon the enemy troops on the march, upon the enemy convoys in the rear, upon his stores and magazines, upon his bridges and railways. Such a bombardment, if it could be continued systematically for long enough, would mean his forced surrender, for retreat would not save him. His aerial foes would be always quicker than he, even his quickest motor transport, and would bombard him from the skies. So that the mastery of the sky would ensure the victory for any army.

The development of the aeroplane is full of the most startling possibilities. Already it has far outflown the vision of its inventors, for, a very short time ago it seems, one of the Voisin frères declared to me that the aeroplane would never be other than a rich man's hobby, of little use in war-time other than the dropping of a few explosives. My informant has since trodden the path of so many brave pilots, but had he lived he would have admitted to-day that the possibilities of the aeroplane seem limitless. The appearance of the Sikorski machine in Russia carrying five or six men in its cabin encourages the belief that the aerobus will soon be a practical reality, and the imagination is fired by the prospect of the air humming with giant aeroplanes, which, by the way, the Germans also attempted to use during the war. There is more than a possibility—so many surprising things have happened—that, in the future, commanders will have aerial motor lorries at their disposal for the rapid transport of their troops. Thus strategy and the physiognomy of the fight would be completely changed. It would effect a complete metamorphosis. The commander who possessed this aerial fleet would be able to carry the whole of his army with the speed and ease of the magic carpet of the Arabian Nights to some distant point and descend even into the enemy country. Nevertheless, as M. Blanchon in the Revue des Deux Mondes suggests, the General who resorted to these aerial methods could not carry out normal military operations for the reason that his matériel must go by road. But when the science of air-transport is sufficiently advanced to allow armies to pass in the sky, presumedly that army will know how to take care of its lines of communication.

These are dreams of the future, however, and their realisation is problematical. But the vision which is in no wise uncertain—the vision which will be realised in the near future, is that of vast armies of wings gathered in the sky. Nations will no longer possess fleets of hundreds of aeroplanes, but tens of thousands will lie in readiness to skim into enemy country and scatter terror and death over vast areas. The nations that plunge into war will no longer pledge only their fighting men; they will enter into battle knowing that their women and children must also endure the worst agony of horror, for modern science has destroyed civilised warfare, and modern man has joined hands with primitive man and wars upon the innocent and helpless.

But it must be conceded that superiority in the machines should be accompanied by superiority in pilots. In a conversation which I had at the time of writing this chapter with M. Louis Blériot (who knows as much as any man living of the practical side of aviation and even its scientific side), the famous winner of the cross-Channel prize confessed that France had not sufficiently developed her rich treasure in expert and adventurous men—the very pick of the pilots of the world—though the English, too, were extraordinary for their sang-froid and were remarkable airmen. For in the air as on the land, in the last resort, it is the personal element which tells. A school, urged Blériot, was necessary to form such super-pilots as Garros and Pégoud, men renowned for ever for their prowess in the air.

For the conquest of the air is to the swift and strong and fearless. Prudence and sagacity, and the slow measured wisdom that comes with the years, play no part in so breathless a pursuit. It is a game for young gods, not for the pale savant; a sport for young eagles, for a man must be sharp of eye, strong of claw and sinews to cleave his way through the clouds, right into the face of day. These super-men who ride fearlessly amongst the stars must be the very pick of humanity, revelling in the sensations of supreme danger, glorying in the knowledge that in a few seconds an assailant may emerge from yonder cloud with whom he must come into death grapples, and well aware that the vanquished will crash down thousands of feet to earth. Youth: youth has been poured out with a lavish hand on the smoking, bloody altar of the war. Youth: there is no incense more precious to the gods. Alas! a monstrous sort of selection is exercised. The young are mowed down by Death with the scythe, leaving the least adventurous, the timid and calculating—those who are sure eventually to die of a cold in the head—to live on.

Very curious is the psychology of the airman. He is billeted so often in the midst of the world in some pleasant little town away behind the lines—it may be even Paris; sometimes also Fate sends him to a château where he lives like a prince amid ancestral halls and a sweeping park—until the day when duty calls him to mount the perilous stairway of the skies to give mortal combat to the enemy. In the trenches men welcome an attack as a relief from the deadly monotony of life in pits, but the airman leaves an easeful, agreeable, social life for the cold, austere atmosphere of the skies under the pure radiant dome of heaven. It requires a man of special temperament to withstand so lively a contrast—not to be softened or unnerved by it. Think of the solitude of the upper air, careering absolutely alone, perhaps. And there is no turning back. There is no such word as "funk" in the bright lexicon of the airman. He is up there because he is fearless, because he does not dread being solus in the wide heavens, because he is a man and no craven, because he has nerves of steel and whipcord. And he must be ready to fight with any weapons. Garros was equally expert in attacking and bringing down his man with machine-gun, carbine, rifle, or even revolver, and in ten days before he was captured he had "grassed" three German aeroplanes. One of the men who fell into his hands having asked him to announce his capture to the German lines, Garros started off in that spirit of chivalry common amongst airmen. There is this delightful about the new arm, it has given a touch of romance to the drab horror of the war. Whenever a man was captured or killed, airmen from the opposite camp dropped a letter informing the comrades of the victim, often with an added word of praise. "Even the Germans are gentlemen in the air," remarked a young pilot the other day. There is chivalry in the air. The man with his head near the stars, flying in immeasurable space, has no room for littlenesses. His heart is large and splendid like the splendour of his deeds—deeds that make the exploits of the old heroes pale into insignificance. They are the phenomenal fruit of a limitless audacity, of a glorious and spring-like youth, of the heyday of existence, when danger is the mad intoxicant, the heady draught that puts brightness into the eye, that gives a riotous pleasure to life, that is like song and wine to the hero clad in the shining and invincible armour of his own superlative freshness and illusions.

The bodies that crash down from the heavens and the souls that soar into the white radiance of Eternity have known no petty thought, have perpetrated no mean deed. Yes, there is chivalry in the Air.

CHAPTER XX