Fig. 82. Sommer biplane.

Photograph by Edwin Levick.

It seems certain that special starting and alighting grounds will be ultimately provided throughout the world. If tramcars must have their stables and their yards, it is not unreasonable to demand the provision of suitable aeroplane stations. Depots or towers will be erected for the storage of fuel and oil, — garages on stilts, in a word. The aviator in need of supplies will signal his wants, lower a trailing line and pick up gasoline by some such device as we now employ to catch mail sacks on express trains.

It may well be that the advent of the flying-machine will have a marked effect on our architecture. Some day houses will be provided with landing stages, assuming that the aeroplane will be able to alight more easily than at present and without the necessity of running along the ground for some distance before it expends its momentum. Ely's remarkable feat in landing on the deck of a warship in the harbour of San Francisco shows that the thing is not remotely possible. When that day dawns, roofs will disappear in favour of flat terraces suited for launching and landing. A business man instead of travelling in a lift from the ground floor of a building to his office on the twenty-first floor, will start from the roof of the building and proceed downward.

Above all things, flying must be safer than it is now. Although the dangers of a sport will inevitably attract to it adventurous spirits, a really commercial machine must satisfy the requirements of the highly nervous man or woman to whom sailing a yacht seems a suicidal pastime.

The early days the bicycle and the automobile industries offer a close parallel to the present position of the aeroplane industry. The pioneers having shown the way, the machine immediately became an instrument of sport. Speed was the thing first desired, and the speed of anything that moves can best be demonstrated in a competition. Bicycle and automobile races became and still are, to some extent, the manufacturer's opportunity of testing and demonstrating the quality of his machines. Long before the manufacture of either touring bicycles or touring automobiles assumed their present proportions, the production of the racing machine was all important. The flying-machine is now in this stage. Races and endurance tests will be the battles from which will emerge the flying-machine of the future, — the machine capable of sustained flights, many hours in duration, at speeds of eighty and one hundred miles an hour. The racer will give birth to the touring flyer, just as the touring car of to-day was evolved from the racing car of five years ago.

Incredible as it may seem, in less than a year from the date when Blériot flew over the English Channel, a feat which set France aeroplane-mad, the actual sales of flying-machines outnumbered the actual sales of automobiles in the first year of their commercial development.

A flying Frenchman clamours for his Blériot or Farman as impatiently as an automobiling American millionaire for his high-powered car, ordered months in advance. The one is no more inclined to bide his time than the other. Hence agents have sprung up in Paris, who order machines from the manufacturer on speculation, and receive as much as $500 to $1,000 above the factory price for immediate delivery. In Paris at least such signs as " Bouvard et Pecuchet, Agents pour Monoplanes Antoinette " can be seen even now, — the harbinger of a great industry of the future and of flying-machine quarters in our large cities.

Compared with the flying-machine of the future, the motor-car will seem as tame and dull as a cart, drawn by a weary nag on a dusty country road. Confined to no route in particular, unhampered by speed restrictions, the speed maniac can drink his fill in the high-powered monoplane. Even the most leisurely of air-touring machines will travel at speeds that only a racing automobile now attains, while the air racer will flit over us, a mere blur to the eye and a buzz to the ear. In an hour or two a whole province will be traversed; in a day a whole continent. An air tourist, a few years hence, will breakfast in Paris and sup the same evening in Moscow. His air-charts, the equivalent of our present road automobile maps will be an atlas, a book in which the air-routes of all Europe are laid down. Swifter than any storm will be his flight. If the black, whirling maelstrom of a cyclone looms up before him, he can make a detour or even outspeed it; for the velocity of his machine will be greater than that of the fiercest of howling, wintry blasts. At a gale which now drives every aviator timorously to cover, he snaps a contemptuous finger, plunges through it in a breathless dash and emerges again in the sunshine, as indifferent to his experience as a locomotive engineer after running through a shower.

The aspect of the heavens will be wonderfully changed when the pleasure plane of the air has arrived. Black specks will dot the blue sky, more like birds than machines, specks that the practised will recognise as impetuous and daring high flyers. Lower down the less reckless will perform their evolutions, and the whirr of their motors will be as the droning of bees, so numerous will they be.

All this deals with the sport. Has the aeroplane no mercantile future? Shall we see flocks of gigantic artificial birds, freighted with heavy cargoes, darkening the sky as they wing their way across the Atlantic or the continent? Will travelling by steamship and railway give way to the aeroplane?

The most sanguine aeronautic engineer would not venture to predict the supplanting of the freight train or the steamer by the aeroplane. For many, many years to come the flying-machine will remain what it is now, a vehicle of sport and war only. Perhaps it may never be anything more. Why? Because it cannot be made big enough. The carrying capacity of an aeroplane depends on its spread of plane. To increase the load means so important an increase in spread that an unmanageable area of supporting surface would be necessary. In order to secure the necessary strength to uphold this increased area an increased weight per square yard is entailed. Hence it is unlikely that aeroplanes carrying many passengers will be built in our time. Not so very long ago Mr. Orville Wright expressed the opinion that aeroplanes " will never take the place of trains or steamships for the carrying of passengers. My brother and I have never figured on building large passenger-carrying machines. Our idea has been to get one that would carry two, three, or five passengers, but this will be the limit of our endeavours".

The late Prof. Samuel P. Langley discovered in the course of his classic experiments that the higher the speed at which a plane travels through the air the less is the supporting surface required. Hence there is a chance that a machine may be constructed in the future which, taking advantage of this law, will be provided with a supporting surface adjustable in area, so that it can start with a large surface, and fold up its planes at full speed. In such a machine the supporting surface would be ultimately reduced until it is a thin edge. We would have an aeroplane propelled by great power, supported largely by the pressure against its body, its wings reduced to mere fins, serving to guide its motion.

As a future commercial possibility, the airship is far more promising than the aeroplane. To the size of the airship there is no limit. Indeed, the larger it can be built the more economically can it be driven, when we measure economy by ratio of carrying power to cost of operation. Just how large an airship can be constructed is a question of constructive engineering. In considering that question the late Prof. Simon Newcomb pointed out that economy is gained only when the dimensions of an airship are so increased that it will carry more than an ocean steamer or a railroad train. To attain that end he estimated that it would be necessary to build an airship at least half a mile in length and six hundred feet in diameter. Such an airship might carry a cargo of ten thousand tons or fifteen thousand passengers. The construction of so huge a craft is not an utter engineering absurdity, remote as it may seem to us now. We recently witnessed something like this when Count von Zeppelin's passenger-carrying airship made a voyage that excited the admiration of the world, even though the vessel was wrecked in a storm. Some fourteen passengers were transported on that remarkable trip, for whom adequate seating and dining accommodations were provided. But the cost of operating such a giant of the air is enormous.

After all is said, money will decide the question of the commercial possibilities of flying-machines and airships. How much does it cost to build? How much does it cost to maintain? How much does it cost to operate? Not until these questions are answered satisfactorily can we tell whether or not the aeroplane will ever be anything more than a racing machine for gilded youth and the dirigible an air-yacht for bankers too old for the more perilous aeroplane.