Gliding along smoothly far above the water, the pa.s.sengers would suffer no uncomfortable seasickness, nor would they be rocked and tumbled about when a storm arose and the waves piled up and up into mountains of water on the surface of the deep. Their craft would move forward undisturbed by the turbulent seas beneath. We can imagine these fortunate individuals of a few years hence, leaning over the railing of their promenade deck as we ourselves might on a calm day at sea, and recalling the great discomforts that used to attend a trans-Atlantic voyage. It is amusing to think that our steamships of to-day will perhaps be recalled by these people of the future about as we ourselves recall the old sailing vessels that used to ply the deep a generation or so ago.

The airplane, if it is to hold its own beside the airship as a large pa.s.senger vessel, will first have to overcome a number of natural handicaps. In the first place, it is not possible to go on increasing the size of the airplane indefinitely, as is practically the case with the airship. For remember that the lighter-than-air machine _floats_ in the air, and only requires its engine to drive it forward: whereas the heavier-than-air machine depends upon the speed imparted to it by its engine and propeller to keep it up in the air at all. Beyond a certain size the airplane would require engines of such enormous size and power to support it that it would be practically impossible to build and operate them. Modern invention has taught us that nothing is beyond the range of fancy, and we have seen many of the wildest dreams of yesterday fulfiled, yet it is safe to say that the airplane which would in any way approximate an ocean liner will not be built for many a year to come. In the meantime, however, we will have huge machines like the Cap.r.o.ni and the Sikorsky triplanes, driven by two or more motors and able to make the trans-Atlantic voyage with a number of pa.s.sengers, freight and fuel for the journey.

Indeed, though for purposes of long distance travel and commerce the airplane stands a chance of being superseded by the lighter-than-air machine, there are many other important missions that it can perform in the modern world. One for which it is particularly suited is that of carrying the mail. In 1911 a Curtiss airplane flew from Na.s.sau Boulevard, Long Island to Mineola, bearing the Hon. Frank H. Hitchc.o.c.k, Postmaster General of the United States, "with a mail bag on his knees."

As the machine swooped gently down over the big white circle that had been painted on the Mineola field, the Postmaster-General let fall his bag. That machine was the pioneer of a system of aerial mail which will soon reach every corner of the country. During the war a mail route was inaugurated between New York and Washington. Now, with many fast machines and trained pilots freed from war duties, a system of routes which will traverse our vast territory has been laid out.

It is for work such as this that the small, fast airplanes developed during the war may prove most successful. Traveling over 100 miles an hour, in a straight line from their starting point to their destination, they will be able to deliver the mail with a speed almost equal to that of the telegraph, and far in excess of anything that can be accomplished by the express train. For not only has the express train much less actual speed, but it must thread its way through winding valleys, go far out of its course in order to avoid some impa.s.sable mountain district, climb steep slopes or follow river beds in order to reach its destination. The airplane has no obstacles to overcome.

Mountains, rivers, impenetrable jungles present no difficulty to it. It simply chooses its objective and flies to it, practically in a straight line. It can jump the Rocky Mountains and deliver mail to the western coast with the greatest ease. Regions like Alaska, where letters from the States took weeks or even months to be delivered, and to which the steamship routes were closed for a portion of the year, will be brought closer home when mails are arriving and leaving every few days.

What use can be made of the large photographing planes that have been developed during the war to such a degree of perfection? In peace times they will have many interesting duties awaiting them. The motion picture producers will no doubt employ them very widely. Flying over our country from end to end they will bring back wonderful panoramic views. They will explore the beauties of the Yukon and show us the peaks of the Rockies in all their majestic grandeur. They will be taken to other continents and sent on photographing flights into regions that have scarcely been trod by human feet, and they will bring home to us remarkable views of jungles where wild animals roam. Pictures which the motion picture man of to-day with his camera has often risked his life to secure, the nimble photographing plane will secure with the utmost ease.

And that suggests another possible role of the airplane in times of peace: that of exploration. As we think of Peary, pushing with his valiant party across the ice fields of the far North, struggling month after month to attain his goal, and returning to the same hard effort each time his expedition failed, we cannot help wishing for his sake that the airplane had reached its present state of development when his difficult undertaking of finding the North Pole began. Who knows but that Peary the pilot might have attained his objective many years before he did, providing of course he had had a machine of the modern type to fly in. Certainly one of the coming uses of the airplane will be that of penetrating into unknown quarters of the earth. Acting on the information which we can thus obtain we may be able to open up new stores of wealth and new territories to man.

The enormous boom that has been given to aircraft production by the war ought to have at least one happy result in peace times: it should reduce the cost of the airplane. When that is brought within the means of the average prosperous citizen, we may expect to see flying become a popular sport. The man who now sets forth on a cross country pleasure trip in his automobile, will find still greater enjoyment in a cross country flight. High above the dusty country roads, he will be able to skim happily through the blue, enjoying his isolation and able to gaze out for many miles in all directions over the beautiful panorama of the earth. The plane which he pilots will no doubt be so designed as to possess unusual stability. It will to a large extent be "fool proof."

Its owner will enjoy the comfortable feeling which comes from a sense of security, and at the same time will have all the delightful sensations of an adventurer in the clouds. He will find the air at high alt.i.tudes invigorating, and so he will gain in health as he never could have done by motoring over the solid earth.

When men take to flying in large numbers no doubt we will have to have some sort of traffic regulations of the sky, but these will never need to be so strict as upon the ground, for the air is not a single track but a wide, limitless expanse, in which airplanes can fly in many directions and at many alt.i.tudes. There will never be any need of pa.s.sing to the left of the machine ahead of you or signaling behind that you are slowing down; for ten chances to one you will never encounter another plane directly in your line of flight, and if you do it will be a simple matter to dive below or climb over him, continuing your journey in a higher stratum of air. There will probably be laws controlling flights over cities and communities, where an accident to the flier might endanger the lives below. What is likely to happen is that certain "highways" of the air will be established legally, extending in many directions over the country. In these directions the private airman will be permitted to fly for pleasure, while at certain intervals along the routes public landing grounds will be maintained.

Landing is still one of the most serious problems the air pilot has to face, and it is to be hoped that the aircraft builders of the near future will help him to solve this difficulty. The reason for it, as we have already seen, is that the airplane secures its buoyancy largely as a result of its speed. Wings which are large enough to support it when flying at 150 miles an hour are too small to hold it in the air when its speed is slowed down. The machine has to be landed while still moving forward at comparatively the rate of an express train, and this forward motion can only be checked after the wheels are safely on the ground. If the engine should be stopped while the airplane is still forty or fifty feet above the ground, the wings would be unable to support it and it would come crashing to the earth. But this situation of course makes matters very difficult for the airman who has not had long experience in landing his machine. He must come down on a small landing field and bring his plane to a full stop before he has crashed into the other machines which perhaps are standing about. His difficulty is added to by the fact that his propeller only works efficiently at the full speed for which it was designed. When he slows down in the air preparatory to landing, it may "slip" backward through the air, instead of driving his airplane forward at the rate necessary to support its weight. In that case he is in danger of going into a spin, from which he may not have time to recover.

For these reasons it is to be hoped that the airplane of the future will have some form of telescoping wings and of variable pitch propeller.

While these improvements in construction have not been worked out practically at the present moment, there is every reason to believe that they may be before long.

But whatever structural difficulties have yet to be overcome in connection with the airplane, certain it is that the big birds which we saw so often in the sky during the war, are going to be yet numerous in peace times. As for the purely military machines, let us hope that their work is over, and that they may never be called on to fight another battle in the air. Yet if other wars should come, it is certain that they would play a still more tremendous role than they have in the present struggle. We can imagine the war of the future being fought almost entirely above the clouds. The one great contest would be for victory in the air, since the nation which succeeded in driving its enemy from the sky would have complete control of the situation on the ground. All nations will continue to increase their aerial battalions until they possess formidable fleets, and it will be these, rather than armies or navies that will go forth to settle future disputes. It is largely to the aerial supremacy of the Allies that we have to give the credit for the winning of the present war against the Hun, and it will be by maintaining their aerial supremacy that the great nations which have taken their stand for justice and humanity will succeed in enforcing the reign of Right in the world.

Thus we see man's dream of the conquest of the air become a n.o.ble thing, while the frail-winged birds his imagination pictured to him throughout so many centuries stand ready to bear him onward and upward to still greater achievements in his struggle to make the world a better and cleaner place in which to live.

READING LIST

For those who desire a wider knowledge of the history, theory, construction and operation of aircraft than this book is intended to supply, the following reading list may prove suggestive and helpful. The older publications on this list have been found valuable from an historical viewpoint; while the more recent ones treat from many angles the rapidly advancing science of aviation.

ABBOT, W. J., Aircraft and Submarines (1918) ALEXANDER, J. H., Model Balloons and Flying Machines (1910) "AVION," Aeroplanes and Aero Engines (1918) BARBER, HORATIO, The Aeroplane Speaks (1917) BARNWELL, F. S., Aeroplane Design (1917) BERGET, A., The Conquest of the Air (1911) BERRY, W. H., Aircraft in War and Commerce (1918) BRUCE, E. H. S., Aircraft in War (1914) CAVANAGH, GEORGE A., Model Aeroplanes and Their Motors (1916) CHATLEY, HERBERT, Principles and Design of Aeroplanes (1912) CURTISS, G. H., and POST, A., Curtiss Aviation Book (1912) CORBIN, T. W., Aircraft, Aeroplanes and Airships (1914) COLLINS, A. FREDERICK, The Boy's Airplane Book (1919) COLLINS, A. FREDERICK, How to Fly (1917) COLVIN, F. H., Aircraft Mechanic's Handbook (1918) DOMMETT, W. E., Aeroplanes and Airships (1916) FALES, E. N., Learning to Fly in the U. S. Army (1917) FERRIS, R., How it Flies (1910) GRAHAME-WHITE, C., and HARPER, H., Heroes of the Air (1912) GRAHAME-WHITE, C., and HARPER, H., Learning to Fly (1916) GRAHAME-WHITE, C., The Story of the Aeroplane (1911) GRAMONT, A. A. DE, Aviator's Elementary Handbook (1918) HAYWARD, CHAS. B., Building and Flying an Aeroplane (1918) HEARNE, R. P., Zeppelins and Super-Zeppelins (1916) HEARNE, R. P., Airships in Peace and War (1910) HILDEBRAND, A. L. H., Airships Past and Present (1908) JANE'S FIGHTING SHIPS, (An Annual) JUDGE, A. W., Design of Aeroplanes (1916) LANCHESTER, F. W., Aircraft in Warfare (1916) LILIENTHAL, O., Bird Flights as the Basis of Aviation (1917) LOENING, G. C., Military Aeroplanes (1916) MCCONNELL, JAMES R., Flying for France (1917) MCMINNIES, W. G., Practical Flying (1918) MAXIM, H. S., Artificial and Natural Flight (1908) MIDDLETON, E. C., The Way of the Air (1917) MIDDLETON, E. C., Glorious Exploits of the Air (1918) MIDDLETON, E. C., Airfare of Today and the Future (1918) MUNDAY, ALBERT H., The Eyes of the Army and Navy (1917) ORCY, L. D', Editor and Comp., Airship Manual (1917) PAGE, CAPT. VICTOR WILFRED, The A-B-C of Aviation (1918) PEARY, R. E., Command of the Air (Speech delivered before the American Academy of Political and Social Science) (1917) RATHBUN, JOHN B., Aeroplane Construction and Operation (1918) ROBSON, W. A., Aircraft in War and Peace (1916) ROTH, C. W., Short Course in the Theory and Operation of the Free Balloon (1918) ROUSTAM-BEK, B., Aerial Russia (1916) SIMMONDS, R., All About Aircraft (1915) STOUT, WM. B., Acquiring Wings (1917) TALBOT, F. A., Aeroplanes and Dirigibles of War (1915) THURSTON, A. B., Elementary Aeronautics (1911) TURNER, C. C., Aircraft of Today (1917) TURNER, C. C., Marvels of Aviation (1916) VERRILL, A. W., Harper's Aircraft Book (1913) WALKER, S. F., Aviation, Its Principles, Its Present and Future (1912) WALKER, F., All About Zeppelins and Other Enemy Aircraft (1915) WIDMER, EMIL J., Military Observation Balloons (1917) WOOD, WALTER, Thrilling Deeds of British Airmen (1918) WINCHESTER, C., Flying Men and Their Machines (1916) WOODHOUSE, HENRY, A Textbook of Military Aeronautics (1918)