_Adjt. Prince_: Then comes the artillery regulating machine. That machine goes up, and it may be a Farman or a bi-motor, or some other kind of heavier machine, a machine that goes slowly. They go over a certain spot. They have a driver, who is a pilot, like ourselves; then they have an artillery officer on board, whose sole duty it is to send back word, mostly by Marconi, to his battery where the shots are landing. He will say: "Too far," "Too short," "Right," or "Left," and he stays there over this battery until the work done by the French guns has been absolutely controlled, and above him he has some of these battle planes keeping him from being attacked from above by German airmen. Of course, they may be shot at by anti-aircraft guns, which you can not help. That is artillery regulating.

_The Chairman_: Are you always attacked from above?

_Adjt. Prince_: By airplanes; yes, sir. It is always much safer to attack from above.

Then you have the bomb-dropping machines, which carry a lot of weight. They go out sometimes in the daytime, but mostly at night, and they have these new sights by which they can stay up quite high in the air and still know the spot they are going at.

They know the wind speed, they know their height, and they can figure out by this new arrangement they have exactly when the time is to let go their bombs.

_Senator Kirby_: Something in the nature of a range-finder?

_Adjt. Prince_: A sort of range-finder.

_Adjt. Rumsey_: It is a sort of telescope that looks down between your legs, and you have to regulate yourself, observing your speed, and when you see the spot, you have to touch a b.u.t.ton and off go these things.

_Adjt. Rumsey_: In a raid my brother went on there were sixty-eight machines that left; the French heavy machines, the English heavy machines, and then the English sort of half-fighting machine and half-bombing machine. They call it a Sopwith, and it is a very good machine. They went over there, and the first ones over were the Frenchmen, and they dropped bombs on these Mauser works, and the only thing that the English saw was a big cloud of smoke and dust, and they could not see the works so they just dropped into them. Out of that raid the fighting machines got eight Germans and dropped them, and the Germans got eight Frenchmen. So, out of sixty-eight they lost eight, but we also got eight Germans and dropped six tons of this stuff, which is twenty times as strong as the melinite. We do not know what the name of the powder is. The fighting machines on that trip only carried gasolene for two hours, and the other ones carried it for something like six hours, so we escorted them out for an hour, came back to our lines, filled up with gasolene, went out and met them and brought them back over the danger zone.

_Adjt. Prince_: Near the trenches is where the danger zone is, because there the German fighting machines are located.

_Senator Kirby_: How far was it from your battle front that you went?

_Adjt. Rumsey_: I think it was about 500 miles, 250 there and 250 back; it was between 200 and 250 miles there.

_Senator Kirby_: Beyond the battle front?

_Adjt. Rumsey_: Yes; or, to be more accurate, I think it was nearer 200 than 250.

_The Chairman_: What do you think of the function of the airplane as a determining factor?

_Adjt. Prince_: There is no doubt that if we could send over in huge waves a great number of these bomb-dropping machines, and simply lay the country waste--for instance, the big cities like Stra.s.sburg, Freiburg, and others--not only would the damage done be great, but I guess the popular opinion in Germany, everything being laid waste, would work very strongly in the minds of the public toward having peace. I do not think you could destroy an army, because you could not see them, but you could go to different stations; you could go to Stra.s.sburg, to Brussels, and places like that.

_The Chairman_: Then, sending them over in enormous numbers would also put out of business their airplanes, and they would be helpless, would they not?

_Adjt. Prince_: Absolutely. You not only have on the front a large number of bomb-dropping machines, but a large number of fighting machines. When the Somme battle was started in the morning the Germans knew, naturally, that the French and British were going to start the Somme drive, and they had up these Drachens, these observation balloons, and the first eighteen minutes that the battle started the French and the English, I think, got twenty-one "saucisse"; in other words, for the next five days there was not a single German who came anywhere near the lines, but the French and English could go ahead as they-felt like.

_Admiral Peary_: Have you any idea as to how many airplanes there are along that western front on the German side?

_Adjt. Prince_: There must be about 3000 on that line in actual commission.

_Admiral Peary_: That means, then, about 10,000 in all, at least?

_Adjt. Prince_: I should think so; I should say the French have about 2000 and the English possibly 1000, or we have about 2500.

_Adjt. Rumsey_: If they have 3000 we have 4000; that is, right on the line.

_Adjt. Prince_: We have about 1000 more than they have, and we are up all the time. The day before I left the front I was called to go out five times, and I went out five times, and spent two hours every time I went out.

It would be gratifying to author and to reader alike if it were possible to give some account of the progress in aerial equipment made by the United States, since its declaration of war. But at the present moment (February, 1918), the government is chary of furnishing information concerning the advance made in the creation of an aerial fleet. Perhaps precise information, if available, would be discouraging to the many who believe that the war will be won in the air. For it is known in a broad general way that the activities of the Administration have been centred upon the construction of training camps and aviation stations. Orders for the actual construction of airplanes have been limited, so that a chorus of criticism arose from manufacturers who declared that they might have to close their works for lack of employment. The apparent check was discouraging to American airmen, and to our Allies who had expected marvellous things from the United States in the way of swift and wholesale preparation for winning battles in the air. The response of the government to all criticism was that it was laying broad foundations in order that construction once begun would proceed with unabated activity, and that when aircraft began to be turned out by the thousands a week there would be aviators and trained mechanics a-plenty to handle them. In this situation the advocates of a special cabinet department of aeronautics found new reason to criticize the Administration and Congress for having ignored or antagonized their appeals. For responsibility for the delay and indifference--if indifference there was--rested equally upon the Secretary of the Navy and the Secretary of War. Each had his measure of control over the enormous sum voted in a lump for aviation, each had the further millions especially voted to his department to account for. But no single individual could be officially asked what had been done with the almost one billion dollars voted for aeronautics in 1917.

But if the authorities seemed to lag, the inventors were busy.

Mention has already been made of the new "Liberty" motor, which report had it was the fruit of the imprisonment of two mechanical experts in a hotel room with orders that they should not be freed until they had produced a motor which met all criticisms upon those now in use. Their product is said to have met this test, and the happy result caused a general wish that the Secretaries of War and of the Navy might be similarly incarcerated and only liberated upon producing plans for the immediate creation of an aerial fleet suited to the nation's needs. If, however, the Liberty motor shall prove the complete success which at the moment the government believes it to be, it will be such a spur to the development of the airplane in peace and war, as could not otherwise be applied. For the motor is the true life of the airplane--its heart, lungs, and nerve centre.

The few people who still doubt the wide adoption of aircraft for peaceful purposes after the war base their skepticism on the treachery of motors still in use. They repudiate all comparisons with automobiles. They say:

It is perfectly true that a man can run his car repeatedly from New York to Boston without motor trouble. But the trouble is inevitable sooner or later. When it comes to an automobile it is trifling. The driver gets out and makes his repairs by the roadside. But if it comes to the aviator it brings the possibility of death with it every time. If his motor stops he must descend. But to alight he must find a long level field, with at least two hundred yards in which to run off his momentum. If, when he discovers the failure of his motor, he is flying at the height of a mile he must find his landing place within a s.p.a.ce of eight miles, for in gliding to earth the ratio of forward movement to height is as eight to one. But how often in rugged and densely populated New England, or Pennsylvania is there a vacant level field half a mile in length? The aviator who made a practice of daily flight between New York and Boston would inevitably meet death in the end.

The criticism is a shrewd and searching one. But it is based on the airplane and the motor of to-day without allowance for the development and improvement which are proceeding apace. It contemplates a craft which has but one motor, but the more modern machines have sufficient lifting power to carry two motors, and can be navigated successfully with one of these out of service.

Experiments furthermore are being made with a device after the type of the helicopter which with the steady lightening of the aircraft motor, may be installed on airplanes with a special motor for its operation. This device, it is believed, will enable the airplane so equipped to stop dead in its course with both propellers out of action, to hover over a given spot or to rise or to descend gently in a perpendicular line without the necessity of soaring. It is obvious that if this device prove successful the chief force of the objections to aerial navigation outlined above will be nullified.

The menace of infrequent landing places will quickly remedy itself on busy lines of aerial traffic. The average railroad doing business in a densely populated section has stations once every eight or ten miles which with their sidings, buildings, water tanks, etc., cost far more than the field half a mile long with a few hangars that the fliers will need as a place of refuge. Indeed, although for its size and apparent simplicity of construction an airplane is phenomenally costly, in the grand total of cost an aerial line would cost a t.i.the of the ordinary railway. It has neither right of way, road bed, rails, nor telegraph system to maintain, and if the average flyer seems to cost amazingly it still foots up less than one fifth the cost of a modern locomotive though its period of service is much shorter.

Just at the present time aircraft costs are high, based on artificial conditions in the market. Their construction is a new industry; its processes not yet standardized; its materials still experimental in many ways and not yet systematically produced. A light sporting monoplane which superficially seems to have about $250 worth of materials in it--exclusive of the engine--will cost about $3000. A fighting biplane will touch $10,000. Yet the latter seems to the lay observer to contain no costly materials to justify so great a charge. The wings are a light wooden framework, usually of spruce, across which a fine grade of linen cloth is stretched.

The materials are simple enough, but every bit of wood, every screw, every strand of wire is selected with the utmost care, and the workmanship of their a.s.semblage is as painstaking as the setting of the most precious stones.

[Ill.u.s.tration: International Film Service.

_A German "Gotha"--their Favorite Type._]

"REMEMBER THE LEAST NEGLIGENCE MAY COST A LIFE!" is a sign frequently seen hanging over the work benches in an airplane factory.

When stretched over the framework, the cloth of the wings is treated to a dressing down of a preparation of collodion, which in the jargon of the shop is called "dope." This substance has a peculiar effect upon the cloth, causing it to shrink, and thus making it more taut and rigid than it could be by the most careful stretching. Though the layman would not suspect it, this wash alone costs about $150 a machine. The seaplanes too--or hydroaeroplanes as purists call them--present a curious ill.u.s.tration of unexpected and, it would seem, unexplainable expense. Where the flyer over land has two bicycle wheels on which to land, the flyer over the sea has two flat-bottomed boats or pontoons. These cost from $1000 to $1200 and look as though they should cost not over $100. But the necessity of combining maximum strength with minimum weight sends the price soaring as the machine itself soars. Moreover there is not yet the demand for either air-or seaplanes that would result in the division of labour, standardization of parts, and other manufacturing economies which reduce the cost of products.

To the high cost of aircraft their comparative fragility is added as a reason for their unfitness for commercial uses. The engines cost from $2000 to $5000 each, are very delicate and usually must be taken out of the plane and overhauled after about 100 hours of active service. The strain on them is prodigious for it is estimated that the number of revolutions of an airplane's engine during an hour's flight is equal to the number of revolutions of an automobile's wheels during active service of a whole month.

It is believed that the superior lightness and durability of the Liberty motor will obviate some of these objections to the commercial availability of aircraft in times of peace. And it is certain that with the cessation of the war, the retirement of the governments of the world from the purchasing field and the reduction of the demand for aircraft to such as are needed for pleasure and industrial uses the prices which we have cited will be cut in half.

In such event what will be the future of aircraft; what their part in the social and industrial organization of the world?

Ten or a dozen years ago Rudyard Kipling entertained the English reading public of the world with a vivacious sketch of aerial navigation in the year 2000 A.D. He used the license of a poet in avoiding too precise descriptions of what is to come--dealing rather with broad and picturesque generalizations. Now the year 2000 is still far enough away for pretty much anything to be invented, and to become commonplace before that era arrives. Airships of the sort Mr. Kipling pictured may by that period have come and gone--have been relegated to the museums along with the stage-coaches of yesterday and the locomotives of to-day. For that matter before that millennial period shall arrive men may have learned to dispense with material transportation altogether, and be able to project their consciousness or even their astral bodies to any desired point on psychic waves. If a poet is going to prophecy he might as well be audacious and even revolutionary in his predictions.

Mr. Kipling tried so hard to be reasonable that he made himself recognizably wrong so far as the present tendency of aircraft development would indicate. _With the Night Mail_, is the story of a trip by night across the Atlantic from England to America. It is made in a monster dirigible--though the present tendency is to reject the dirigible for the swifter, less costly, and more airworthy (leave "seaworthy" to the plodding ships on old ocean's breast) airplanes. If, however, we condone this glaring improbability we find Mr. Kipling's tale full of action and imaginary incident that give it an air of truth. His ship is not docked on the ground at the tempest's mercy, but is moored high in air to the top of a tall tower up which pa.s.sengers and freight are conveyed in elevators. His lighthouses send their beams straight up into the sky instead of projecting them horizontally as do those which now guard our coasts. Just why lighthouses are needed, however, he does not explain. There are no reefs on which a packet of the air may run, no lee sh.o.r.es which they must avoid. On overland voyages guiding lights by night may be useful, as great white direction strips laid out on the ground are even now suggested as guides for daylight flying. But the main reliance of the airman must be his compa.s.s. Crossing the broad oceans no lighted path is possible, and even in a voyage from New York to Chicago, or from London to Rome good airmanship will dictate flight at a height that will make reliance upon natural objects as a guide perilous. The airman has the advantage over the sailor in that he may lay his course on leaving his port, or flying field, and pursue it straight as an arrow to his destination. No rocks or other obstacles bar his path, no tortuous channels must be navigated. All that can divert him from his chosen course is a steady wind on the beam, and that is instantly detected by his instruments and allowance made for it.

On the other hand the sailor has a certain advantage over the airman in that his more leisurely progress allows time for the rectification of errors in course arising from contrary currents or winds. An error of a point, or even two, amounts to but little in a day's steaming of perhaps four hundred miles. It can readily be remedied, unless the ship is too near sh.o.r.e. But when the whole three thousand miles of Atlantic are covered in twenty hours in the air, the course must be right from the start and exactly adhered to, else the pa.s.senger for New York may be set down in Florida.

It is not improbable that even before the war is over the crossing of the Atlantic by plane will be accomplished. Certainly it will be one of the first tasks undertaken by airmen on the return of peace.

But it is probable that the adaptation of aircraft to commercial uses will be begun with undertakings of smaller proportions. Already the United States maintains an aerial mail route in Alaska, while Italy has military mail routes served by airplanes in the Alps.

These have been undertaken because of the physical obstacles to travel on the surface, presented in those rugged neighbourhoods. But in the more densely populated regions of the United States considerations of financial profit will almost certainly result in the early establishment of mail and pa.s.senger air service. Air service will cut down the time between any two given points at least one half, and ultimately two thirds. Letters could be sent from New York to Boston, or even to Buffalo, and an answer received the same day. The carrying plane could take on each trip five tons of mail.

Philadelphia would be brought within forty-five minutes of New York; Washington within two hours instead of the present five. Is there any doubt of the creation of an aerial pa.s.senger service under such conditions? Already a Cap.r.o.ni triplane will carry thirty-five pa.s.sengers beside guns--say, fifty pa.s.sengers if all other load be excluded, and has flown with a lighter load from Newport News to New York. It is easily imaginable that by 1920 the airplane capable of carrying eighty persons--or the normal number now accommodated on an inter-urban trolley car--will be an accomplished fact.

The lines that will thus spring up will need no rails, no right of way, no expensive power plant. Their physical property will be confined to the airplanes themselves and to the fields from which the craft rise and on which they alight, with the necessary hangars.

These indeed will involve heavy expenditure. For a busy line, with frequent sailings, of high speed machines a field will need to be in the neighbourhood of a mile square. A plane swooping down for its landing is not to be held up at the switch like a train while room is made for it. It is an imperative guest, and cannot be gainsaid.

Accordingly the fields must be large enough to accommodate scores of planes at once and give each new arrival a long straight course on which to run off its momentum. It is obvious therefore that the union stations for aircraft routes cannot be in the hearts of our cities as are the railroad stations of to-day, but must be fairly well out in the suburbs.

A form of machine which the professional airmen say has yet to be developed is the small monoplane, carrying two pa.s.sengers at most, and of low speed--not more than twenty miles an hour at most. In this age of speed mania the idea of deliberately planning a conveyance or vehicle that shall not exceed a low limit seems out of accord with public desire. But the low speed airplane has the advantage of needing no extended field in which to alight. It reaches the ground with but little momentum to be taken up and can be brought up standing on the roof of a house or the deck of a ship.

Small machines of this sort are likely to serve as the runabouts of the air, to succeed the trim little automobile roadsters as pleasure craft.

[Ill.u.s.tration: International Film Service.

_A French Monoplane._]

The beginning of the fourth year of the war brought a notable change in aerial tactics. For three years everything had been sacrificed to speed. Such aerial duels as have been described were encouraged by the fact that aircraft were reduced to the proportions needful for carrying one man and a machine gun. The gallant flyers went up in the air and killed each other. That was about all there was to it.

While as scouts, range finders, guides for the artillery, they exerted some influence on the course of the war, as a fighting arm in its earlier years, they were without efficiency. The bombing forays were hara.s.sing but little more, because the craft engaged were of too small capacity to carry enough bombs to work really serious damage, while the ever increasing range of the "Archies"