I. Flights in thirty-five-mile-an-hour winds—Arguments of sceptics—What the great contests of 1911 proved.

Reference has been made to the fact that, as soon as engines became reliable, and airmen gained confidence, winds of an appreciable velocity were successfully combated.

But even now, despite the strides which the aeroplane is making towards becoming an all-weather machine, those who belittle it from the military point of view, and uphold an official policy of inactivity, are found ready to argue that the heavier-than-air machine is still purely a fine-weather craft. Such an attitude is governed, not so much by deep-rooted conservatism, as by ignorance.

The fact is that the wind-flying capabilities of an aeroplane have been improved to an altogether remarkable extent. So far as an average can be struck, it may be said that, at the present time, a war machine can be operated, and can carry out useful work, in a wind blowing at the rate of from thirty to thirty-five miles an hour. Higher winds are, as has been said, occasionally combated; but this represents, approximately, the maximum for practical purposes to-day.

Some military critics, when such facts as these are adduced, raise the point that such "air-worthiness" as this is not sufficient. The complications of war are already so great, they declare, that a Commander-in-Chief is not justified in increasing his responsibilities by saddling himself with a squadron of aeroplanes, when the machines will be inoperative should a high wind spring up.

"Enthusiasts do not seem to realise this point," a military critic has observed, in regard to the general question of aeroplane reliability. "A commander of troops would, almost, be more hampered than helped by an air service, were it only possible to use it one day, and then not the next, and so on. He would rely upon it, you see, and then it would fail him just at some critical moment. I know it may be said, in answer to this, that even if only occasional use can be made of aeroplanes, it is worth while to equip an army with them, because, if they succeed in their object once in six times, they may alter the whole course of a battle. But it must be remembered that a very considerable organisation has to be built up, if an aeroplane service is to be of any real use. The already huge impedimenta of an army has to be added to; and this, alone, is a very serious point. On account of the unreliability of the air service, also, cavalry scouts, and other scouting agencies, have to be employed, just as usual. The position is, really, a somewhat unsatisfactory one. For days on end, if the weather is bad, the aeroplanes may be inoperative."

This view is, of course, an unduly pessimistic one.

Having regard to the capabilities of present-type aeroplanes, the occasions upon which war machines would be windbound would be very rare. It is reliably estimated, in fact, that aeroplane scouts would be able to render good service on 80 per cent, of the days of the year.

It might happen that a boisterous wind, rising in the morning, would prevent the air-scouts from working at midday, or during the afternoon. But, even during a generally unfavourable spell of weather, a shrewd Commander of aeroplanes should be able to snatch an hour's lull in the wind, probably in the early morning or evening, and get his machines to work.

Either a morning or evening calm, during a period of gusty winds, is generally experienced; and, in any such lull, so rapid is their work, the aeroplanes should be able to acquire what information is necessary, and be back again at Headquarters, before any hazardous rising of the wind takes place.

In this way, it should be possible to manipulate the service, even with existing machines, so as to make it of practical value, upon almost every day of a campaign; and the fact that one hour's work would probably be sufficient for a reconnoitring flight, is the important factor of the situation to be remembered.

The point to be made in this connection is this: those who have studied the progress of aeroplaning, and realise the wonderful strides which have recently been made, see quite clearly that, even under unfavourable conditions, a war machine should be able to give a very good account of itself.

This fact will not be admitted, however, by those who still maintain the attitude that the aeroplane is a fair-weather machine, and will never be anything else. Their prejudice will not permit them to read, as they should, the lessons of recent events. They magnify failures, and ignore successes.

For such a negative policy there was, at first, some excuse, although scepticism, at the dawn of a new industry, is the reverse of helpful. When aeroplanes were in their crudest stage, they provided plenty of material for the cynic. In those days, pilots spent most of their time in their hangars, tuning up obstinate engines; and it was a case, as one humorous pioneer put it, of flying "a mile a month."

The prevailing spirit of scepticism was well revealed in the attitude taken up by many people in connection with the prize of £10,000 offered by The Daily Mail for the flight from London to Manchester. To imagine that such a feat would be accomplished was regarded as ridiculous. And yet, practically at the first attempt, the flight was made. Then came the second £10,000 prize by the generous and far-seeing proprietors of The Daily Mail—this time for a 1000-miles aerial tour around Great Britain, in which rules were introduced to make it incumbent upon pilots to complete the whole course upon one machine.

Here was a leap, indeed. From 180 miles to 1000! Could it be done? Could such a reliable aeroplane be found? These were the questions asked; and, in this connection, one significant fact may be mentioned. It was this: even some of the experts—men thoroughly well acquainted with the industry—were doubtful as to whether this prize would be won. They knew, of course, what giant strides were being made. But, still, so severe was the ordeal, they had their doubts.

What a triumph this great contest was for the aeroplane will be fresh in any reader's memory. Flying neck and neck round the 1010-miles course, Beaumont and Vedrines astonished the world by the certainty of their aerial progress.

Calculations as to when the race would finish had been made beforehand. Reckoning the very highest speeds it would be possible to attain, and assuming an entire absence of mechanical troubles, it was estimated that the winner would complete the circuit at a certain hour on a specified morning; and the winner, Beaumont, was only four hours longer, in completing the course, than the most favourable estimate had allowed him.

Even the most enthusiastic supporters of the aeroplane were astonished by this feat. In flying, which was spread out over several days, and involved aerial journeys over most difficult country, Beaumont and Vedrines made light of every adverse condition. In Scotland, they combated winds so violent that their machines danced and plunged in the air, and occasionally "side-slipped" for many feet under the treacherous impulses of unexpected gusts. But, when they were begged to wait a while, and give the weather an opportunity of improving, these two champions resolutely took their seats in their monoplanes, and flew on. The lesson, from the military point of view, was overwhelmingly important.

Not only did these two men fly with the regularity and speed of express trains, but they both performed their wonderful feats on machines which were unchanged throughout. This represented the real progress. In previous contests of a similar nature, in which long distances had been traversed, there had been no restriction at all as to the number of machines used.

The result had been, therefore, that makers of aeroplanes, naturally anxious to see their representatives win, had dotted spare machines all over the route; and, in one instance, a competitor used as many as three aeroplanes before completing one long-distance race.

The point we are immediately concerned with is this. A certain number of days, chosen a long time ahead, were set apart for this 1000-miles race round Great Britain; and upon these days it was flown. Beaumont and Vedrines proceeded from stage to stage, flying to schedule, and making light of adverse weather. The climatic conditions, as has been said, were not ideal. When the time came to leave Edinburgh, for instance, so powerful a wind was blowing that it was not reckoned, even by practical men, that the pilots would be able to get away.

But, to the amazement even of officials, the two monoplanists soared up, and deliberately fought the wind. While flying on to the other stopping-places in Scotland, also, both men passed through heavy storms of rain; and again, contrary to expectation, they did not descend, but battled on. The result was that, when this wonderful air race was at an end, both men were justified in describing their monoplanes as all-weather machines.

What this performance, and others, have demonstrated is this: at the present moment, although admittedly experimental, the aeroplane is sufficiently well able to combat adverse weather as to make it a highly-useful weapon of war.

II. Value of high speed, when combating a wind—Constructional difficulties of a hundred-mile-an-hour machine.

It is unwise to regard the capabilities of the present-type aeroplane as representing, in any way, a limit, or a standard of achievement. What the machine built to-day can perform, the aeroplane of to-morrow will, assuredly, be able to improve upon; and so progress will be recorded, until something in the nature of a perfected aircraft is evolved.

As a matter of fact, there is practically no stage, in connection with any forms of manufacture, when a builder can say: "Here is a machine incapable of improvement." Take, as an example, the motor-car. The luxurious, six-cylindered machine appears to represent what may be termed "the last word"; but small improvements are constantly being made, and thoughtful manufacturers still see new avenues of progress.

So it is in regard to the wind-flying capabilities of an aeroplane. Thirty to thirty-five miles an hour represents, as has been said, a fair maximum for the strength of wind in which a machine can be navigated at the present time. But this will not exist long as a standard; improvements in the speed, and in the general stability of machines, are being made from day to day.

The result of this progress in manufacture will be that the aeroplane will be navigable in higher and higher winds. Forty-mile-an-hour winds will, before long, cease to prevent regular flight; and it is the view of eminent designers and builders that it will be possible for the aeroplane to remain aloft in winds blowing at the rate of more than fifty miles an hour. It is hoped, in fact, that machines will, eventually, be able to live in any wind save such a raging gale as drives big steamships to port.

Already, certain definite lines of improvement suggest themselves to the makers of aeroplanes. In combating a high wind, failing any device to provide an aeroplane with automatic stability, high speed is found to be of the greatest aid. But there are difficulties in connection with the attaining of high speed, as will be shown later.

An illustration of the value of high speed, in overcoming the wind, was giving at the Rheims flying meeting in the summer of 1910. Morane, testing a monoplane fitted with a motor of a hundred horse-power, attained a speed of quite eighty miles an hour. Travelling at this rate, he found that he was able to pass close behind other machines, despite the rush of wind from their propellers. Had he been flying a slower machine, this "back-draught" would, inevitably, have caused him to capsize.

Speed, also, was what helped Beaumont and Vedrines, when they were fighting adverse winds in the Circuit of Britain. Beaumont's monoplane had a speed of a little over sixty miles an hour; and that of Vedrines was a trifle faster. Had either of these airmen been piloting a slow-flying biplane, he would have been forced to descend, seeing that his machine would have become unmanageable in heavy gusts.

Speed, therefore, is the aim of most manufacturers. They see that the aeroplane must, if it is to compete commercially with land or sea transit, provide a means of locomotion more rapid than any which at present exists; and they recognise, also, that speed offers—at any rate at present—a solution of the problem of all-weather flying.

But there are, as has been hinted, difficulties in the way of large increases in speed. Two hundred miles an hour through the air is, frequently, cited as the ideal to be aimed at. So far, with a specially-built racing machine, a speed of approximately a hundred miles an hour has represented the maximum attained. Such machines are, however, more or less "freaks"; the best results obtained with ordinary machines being from sixty-five to seventy miles an hour.

Higher speeds still might be thought to be merely a question of increasing horse-power. But other considerations enter into the question. A high-speed machine has, it must be remembered, to start away from the ground, and land again at the end of a flight; its actual passage through the air is not the only point to be considered.

With a racing monoplane, for example, the small size of its supporting wings, and the slight camber upon them, necessitate its moving over the ground at a very high speed before it can obtain the necessary "lift" to get into the air; and then comes the question of returning to the ground again. These fast machines will only glide at comparatively high speeds.

A problem arises, therefore, as to the landing chassis which will withstand the shock of high-speed landings—that is to say, on anything save perfectly smooth ground. Apart from the question of the skill of the pilot, in effecting a safe descent at such high speeds—and this is a factor seriously to be reckoned with—the running-wheels and skids of a machine will not endure the strain of a landing on anything like a rough surface.

Thus, were speeds to be pushed, say, to a hundred and fifty miles an hour, under present conditions of flying, and with any existing method of building landing mechanism, accidents would be likely to happen, when airmen came to the point of effecting a descent.

Also to be reckoned with, is the question of increasing the structural strength of machines in order to meet the wind pressure of very high speeds.

III. Variable-speed aeroplane—Plans for constructing aircraft of this type—Advantages of such a machine.

As regards the problem of a fast, and yet reliable aeroplane, which is an especially important one from the military point of view, seeing that machines will need to operate over all sorts of country during a campaign, the view is now taken, by eminent manufacturers, that something in the nature of a variable-speed aircraft will need to be devised.

If this can be evolved, it certainly promises a solution of the problem. What the question resolves itself into, as can be seen, is this: there are very distinct limits to the rate at which it is practical to move across the ground on preparing to soar, and also to the speed at which it is feasible to return again to earth.

The variable-speed machine seems destined to meet these difficulties, and makers are busy with plans for the building of aeroplanes of this type. The immediate aim is to produce, if possible, an aeroplane with a maximum speed approaching, say, a hundred miles an hour, and a minimum speed of about thirty miles an hour.

In this way, adequate use would be made of the air as a speed medium and, at the same time, it would be possible to effect satisfactory landings on fairly rough ground, as well as on smooth surfaces. For the production of such a variable-speed machine, several designs have already been prepared; but, as yet, each awaits the ordeal of a practical test.

One plan, for example, involves the altering of the angle of incidence of the planes, while a machine is in flight. The angle would, that is to say, be made steep for slow flight, and flatter when high speed was required. Another device aims at obtaining variable speed by a process of reefing the planes of a machine. This would be done by reducing, or rolling up, the rear extremities of the plane surfaces.

According to this system, a machine would have its slowest speed when its maximum amount of sustaining surface was in operation, and would fly faster as the pilot gradually brought into play the reefing process.

A third scheme which is suggested deals with the telescoping of the plane-ends of a machine, thereby reducing the lifting surface.

Of these methods, the one most favoured, having regard to its practicability, is that of slightly altering the angle of the planes; and several manufacturers are already busy with experimental machines of this type. It appears likely that actual tests will, before long, be attempted with an aeroplane thus equipped.

For military work, a variable-speed machine promises to be exceptionally useful. The high speed would be employed in weathering a gusty wind, or in moving rapidly to any desired locality, when about to carry out a reconnaissance. Then, when a detailed observation was being made, the slowest speed would be adopted, so as to give the observer plenty of opportunity of studying what lay below him.

The production of a practical machine, embodying the principle of variable speeds, is now held to be merely a question of time, and of careful experiment. Therefore, the promise of the immediate future, particularly as regards the military aspect of flying, is most hopeful—both from the point of view of wind-flying, and of reliability.

One by one, indeed, the objections against the military aeroplane are likely to be overcome, until a machine is an accomplished fact which will meet all practical requirements.

IV. Power-plant of aeroplanes—Fitting two engines to obviate involuntary descents.

While writing of aeroplane development, mention should certainly be made of engines. It has been shown, already, what a wonderful step forward was made with the introduction of the revolving "Gnome." This engine will operate with the reliability of that fitted to a motor-car; there are other types of engine now achieving thoroughly good results; and they promise to do better in the future. From the point of view of propulsion, therefore, the future of the aeroplane appears assured.

One great objection of sceptics, in regard to the power-plant of aeroplanes, has been that, should an engine fail, a machine is compelled to make an involuntary descent. In answer to this criticism, advocates of the aeroplane have pointed out that motors are becoming more and more reliable, and that such stoppages are already reduced to a minimum.

It is now seen that it will be possible to prevent involuntary descent, when flying across country, by equipping aeroplanes with a reserve powerplant.

One of the most interesting experiments, in this regard, is being carried out by Mr Horace Short, the aeronautical engineer of the Royal Aero Club.

Mr Short produced, in September, 1911, a biplane fitted with two "Gnome" engines. One, placed in front of the machine, operated a couple of tractor propellers fitted before the main-planes. The other, installed at the rear, actuated a single propeller. The machine was designed so that one engine would drive it at a speed of about thirty-six miles an hour; while, if both were employed, its pace would increase to more than fifty miles an hour. In actual tests, most encouraging results were obtained with this machine, and Mr Short is now perfecting this type of twin-engine biplane.

By equipping an aeroplane with two engines, working independently of each other, the danger of an involuntary descent, on bad ground, is obviated.

Should one engine stop, the pilot can keep himself in the air with the other.

In such a machine as this, which might be described as a "safety" aeroplane, the weight of the additional engine is, of course, a consideration, but in cases where exceptional reliability is required—say, for example, when a most urgent dispatch has to be taken across country from point to point in military operations—a dual-engine machine will probably be used.

Consideration of such facts as have been cited in this section show that aeroplanes, for military work, have an almost unlimited field for improvement. Therefore, any nation which neglects war machines now, on the argument that they are unreliable, is pursuing an extremely foolish policy. If feats such as have been recently accomplished are possible, with machines built with wood, wire, and canvas, what will not be achieved with the stronger, speedier, heavier aeroplanes, such as are already being constructed?

Sceptics there are, of course, who may be found ready to say that the aeroplane will never be made reliable; but their contentions are being proved to be wrong from day to day. Already, with the simplest possible apparatus, a remarkable stage of efficiency has been reached. And now the aeroplane promises to embark upon a new era of construction.

Wood is being replaced by metal; and extreme lightness is no longer the insistent demand. Aeroplanes are being built for general, everyday use.

From the military point of view, the aeroplanes at present available have drawbacks. There is, indeed, room for vast improvement. Greater strength, greater reliability, greater portability—these are the aims that makers have in view; and they will, without doubt, be realised.

The War Office tests this summer will teach manufacturers many a useful lesson.