I. What a modern-type machine can raise—Load of two men, and explosives.

In previous sections, the reconnoitring capabilities of the war aeroplane have been dealt with; but there is now another, and an increasingly-significant aspect of its work. This lies in its power of destruction.

In its early stages, the aeroplane could, only with difficulty, raise its pilot from the ground; any weight-lifting was out of the question. But, with the development of engines, and the efficiency of machines generally, the carrying of appreciable burdens has come within the range of practical politics.

A biplane can be constructed, at the present time, which is capable of raising a pilot, an engineer, and a load of explosives, and of flying, thus loaded, for several hours without descending.

Not long ago, it was predicted that a fleet of weight-carrying aeroplanes might be able to leave foreign soil one day, fly over London, drop a quantity of explosives on the city, and return—by way of the air—whence they came.

When this prediction was first made, it was generally considered in the nature of an impossible dream. But, nowadays, it has ceased to be a wildly-improbable undertaking. With aeroplanes such as could be built at the present time, an expedition of this character could, as a matter of fact, be carried out.

But the aeroplane must first be perfected as a scouting machine. Afterwards, may come its application as an offensive weapon. To ignore the destructive aspect of military flying is, however, foolish.

Foreign countries realise such possibilities; already, tentative experiments are being made. When reckoned singly, aeroplanes have an insignificant value as engines of destruction; but, when bomb-dropping machines are employed in large, well-organised squadrons, a different situation arises. It is in regular fleets that attacking machines of the future will, almost certainly, be employed.

It was in 1909, after his cross-Channel flight, that M. Louis BlÉriot declared: "Before long, military and naval aeroplanes will be able to carry explosives of the deadliest nature." This shrewd man saw what lay in the future. At the time he spoke, a flight of an hour's duration, by a machine carrying only one man, was an achievement; but, nowadays, a heavily-laden machine can remain aloft for a number of hours.

Bomb-dropping mechanism, to facilitate the discharge of a missile from an aeroplane, has been devised. The bombs are contained in a chamber beneath the aeroplane, and pass thence into a tube, which is pointed towards the ground. By pressing a button, conveniently close to his driving-seat, the airman is able to release a series of bombs over a given point. Missiles in the form of carefully-weighted arrows have also been employed—the explosive forming the head of the arrow, and the projectile being released from a special form of sighting mechanism. With this apparatus, fairly good practice has been made, from heights in the neighbourhood of 500 feet.

The experiments so far made, in connection with dropping bombs, show that considerable practice is necessary before accurate aim is possible. In actual attacks in warfare, however, absolute precision would not always be an essential. A detachment of machines would probably pass, one after another, over a given position, raining down missiles as they swept by. The aim would be made as accurate as possible, of course; but the telling nature of the attack would be, not in the chance of individual bombs reaching any precise mark, but in the fact that a large percentage of the missiles would be calculated to do damage over a given area.

Among experts in France and Germany, who are now paying keen attention to this question of a destructive war aeroplane, it is considered that an incendiary bomb would work great havoc in wartime. The possibility of employing some such bomb as this was suggested by Lord Charles Beresford, after he had witnessed the demonstration organised by the Parliamentary Aerial Defence Committee in May, 1911. He foresaw that aeroplanes might be able to drop cylinders of some highly-inflammable spirit, ignited by a sensitive fuse, and calculated to cause an instant and violent conflagration.

As a matter of fact, it has already been realised that several types of bomb are likely to be employed in aerial warfare, according to the targets which are aimed at. In an attack upon supply stores, for example, an incendiary bomb may be used, so that the contents may be set on fire, and destroyed; and the same kind of missile will probably be dropped upon dockyards, arsenals, and magazines.

For the destruction of bridges, for the attack upon troops on the march, and for the bombarding of encampments, some special form of explosive shell may be used. Definite choice of such a shell has not yet been made; but here, again, experimental work has already been commenced abroad.

In England, realising the importance of this question. Sir Hiram Maxim has recently been engaging himself with the production of a 100-lb. aerial projectile likely to create a maximum amount of damage when striking the ground.

Aerial bombardment, if systematically carried out, will certainly add another terror to modern war; and the question is sometimes asked whether nations have a right, according to the agreements of the Hague Convention, to employ such a means of attack. The position, so far as the last convention was concerned, was that certain nations, notably France and Germany, did not become signatories to a rule, proposing that aerial bomb-dropping should be disallowed.

Such a practical airman as M. Vedrines is enthusiastic regarding the offensive powers of a modern aeroplane, when skilfully handled. His view is that a large and well-organised squadron of weight-carrying machines should be able to render almost useless a fleet of ships.

Naval men would, no doubt, regard such a statement as being an exaggeration. The aim of an aeroplanist, when directing his bomb against a moving ship, would frequently be inaccurate, they claim; and they also affirm that an aeroplane would not be able to carry bombs sufficiently large and deadly to do much damage, even if one did, occasionally, reach its mark.

But here the argument is based upon the possible use of one machine, and not of a fleet. One aeroplane, dropping a few bombs on a fleet of ships, would naturally produce an insignificant result. But what of the results achieved by several hundred, and perhaps of a thousand? In such a case, there would not be one bomb to contend against, but a volley of missiles.

M. Vedrines, whose opinion was quoted above, is a believer in the speed of the aeroplane, as aiding its powers of attack. In regard to a possible war between France and Germany, he has declared that, within an hour of the declaration of such a war, a corps of French airmen could be over the frontier, attacking, with their bombs, all great railway junctions and forts on German soil.

The rapidity with which an aeroplane onslaught can be made should, indeed, prove one of the most important features of aerial warfare. Destructive machines may fly from their Headquarters, deliver an attack fifty or a hundred miles away, and—their ammunition exhausted—return quickly to their base for more, and so be ready to renew the attack.

II. Effect of aerial bombardment upon cities and troops—German tests.

It was after a seven years' study of military aviation, as Commandant of the British Government Balloon School, that Colonel J. E. Capper declared emphatically: "The necessity has arisen for every warlike nation to have a sufficient aerial fleet, armed and equipped for offensive warfare."

His advice, however, was not adopted—at any rate, not by the War Office. No steps have yet been taken to estimate the value of an aeroplane as a destructive instrument, despite the fact that France and Germany are keenly alive to the possibilities of a large number of weight-carrying machines.

In Germany, at the present time, secret tests and experiments are being made, and the construction of special machines undertaken. Meanwhile, we fumble along. If a war broke out to-morrow, it is true that destructive work by aeroplanes, on anything like a large scale, would not be undertaken.

But what about the day after to-morrow—or rather next year? Every day, the general efficiency of the aeroplane is being improved, and its radius of action increased. Practically every day, also, foreign nations are adding to their air-fleets. Already the art of employing aircraft in fairly large numbers has been learned. Machines for destructive work can now be built—and are being built; and yet we are content, as yet, to do nothing.

Sufficient warning has been given. Colonel Templer, an officer identified with the first Government aeronautical work undertaken in England, has declared: "It is conclusively proved that the aeroplane is a machine for carrying out attacks in warfare. We must, therefore, be prepared not only for defence against bomb-dropping aeroplanes; we must be prepared, if necessary, to use them."

Another military expert of high repute, speaking of the havoc that a hostile air-fleet might work, by an attack upon the Thames Valley between Hammersmith and Gravesend, has observed: "This whole fifty miles of concentrated essence of Empire lies at the absolute mercy of an aerial machine, which could plant a dozen incendiary missiles in certain pre-selected spots."

The point to be considered, in this connection, is this: such an aerial attack is no longer a vague possibility. It was only the other day, while discussing the destructive capabilities of modern-type aeroplanes, that a famous constructer showed how—if a large fleet of machines was marshalled together—it would be possible for an enemy to drop a couple of hundred tons of explosive matter upon London, suddenly appearing from across the Channel by air, and as flying quickly back again.

What such an aerial attack as this would mean has been pictured by Lord Montagu of Beaulieu. Suppose London was thus assailed, from the air, at the beginning of a war, he says: What would the result be? Imagine the Stock Exchange, the chief banks, the great railway stations, and our means of communication destroyed. "Such a blow at the very heart of the Empire," declares Lord Montagu, "would be like paralysing the nerves of a strong man, with a soporific, before he had to fight for his life: the muscular force would remain, but the brains would be powerless to direct."

When delivering an attack upon a city, a squadron of aeroplanes engaged in such work would, declare military experts who have specially studied the problem, probably sweep over the principal buildings in a long line, dropping bombs as they flew. Then they would wheel round, and return over the same area, again releasing a certain number of missiles. The disastrous effect of such an aerial bombardment, carried out systematically by a large number of machines, may readily be imagined.

Although, as has been mentioned, German experimental work, regarding the value of aeroplanes for punitive work, has been kept very secret, the result of one interesting test, at least, has become known. In this case, a squadron of dragoons was specially employed to give realism to the experiment.

The squadron was directed to move a certain distance away from one of the German air-stations, and then camp for the night. This was done. Then two army airmen, flying biplanes, set off to deliver a night attack upon the encampment. Beneath their machines, they carried a bomb-dropping apparatus such as has already been described.

Locating the bivouac by its fires, the two airmen stopped their engines, and planed down silently from a considerable altitude. Neither of the aeroplanes was seen, by the dragoons, until it was right over them. Then the attacking airmen released a stream of dummy bombs, which fell all about the camp-fires. Immediately they had done so, and before the dragoons had recovered from their surprise, the pilots started their engines, and disappeared again into the darkness.

Seeing that it was purely experimental, and that neither officer-airmen was skilled in such work, the result of this mock attack was surprising. Had actual war conditions prevailed, and had the bombs been real ones, death would have been scattered through the bivouac, the horses would probably have stampeded, and a general scene of confusion would have ensued.

And this is a most important point: so swift and unexpected was the night attack that the machines only came into view just at the moment they were releasing their bombs. This would probably have meant that, in warfare, they would have escaped without an effective shot being fired at them.

By such tests as these, regarding which, as a general rule, nothing becomes public, the German military authorities are obtaining data that is invaluable concerning the destructive potentialities of the war aeroplane. Apart from the actual damage done by such a night attack as has been described, there is its moral effect to be considered—and this point is regarded as an important one by foreign experts.

Nothing, they think, could be more harassing or wearying for troops, during a hard campaign, than to be attacked, night after night, by squadrons of aeroplanes. Incessant watchfulness, and consequent loss of rest, would be involved, and a general feeling of uneasiness would be occasioned.

It is now considered feasible to carry a light machine-gun upon an aeroplane, and to use it effectively. With such guns, skilfully handled, it is considered that attacks could be delivered upon reserve troops, upon artillery trains, upon the horses of guns in action, and upon troops when on the march.

Considerable experience, in handling a machine-gun on an aeroplane will, probably, be necessary before accuracy can be obtained; but military men, who are most competent to speak, see no difficulty in equipping an aeroplane with such a gun, and in obtaining satisfactory results.

In conclusion, it may be taken that the offensive possibilities of the aeroplane grow, from day to day. Machines are built to fly faster, and to carry heavier weights. In future, so far as the question of this destructive work of machines is concerned, it will be necessary to reckon air-fleets not in hundreds, but in thousands.

At the moment, as has been said, the reconnoitring machine is engaging most attention; but an aeroplane for destructive use is being kept well in mind, none the less. Its appearance, as a weapon of war, is merely a matter of time.

What may be accomplished, by a fleet of aeroplanes bent upon destruction, has only been hinted at in this section; but it should serve its purpose—which is to show that no country can afford to ignore what the future promises in this respect.