speeds of 150 and 200 miles an hour ultimately to be attained. From varying a craft's plane-area, while in flight, are anticipated. important results The system, which is based upon the fact that, as its speed increases, the planes of a machine exert greater lift --may be explained, briefly, thus: at ascending, or in alighting, when moderate pace is desirable, the aircraft would expose its whole wing surface; but when aloft, and with motors developing full power, the planes would be reefed by degrees, or furled-so that, as less lifting surface became required, the machine would adapt itself, without wastage of propelling effort, to the gradually growing speed. Without some method such as this, an aircraft's flying speed is governed by the pace at which it is practicable to rise from, or descend upon, the ground. With fast flying machines. for instance, as at present constructed, difficulty is experienced in alighting, unless the landing surface is perfectly smooth. Aeroplanes, in fact, like motor-cars, need a system of changing speeds, if efficiency is to be achieved. Obstacles to be overcome, in constructing variable-speed craft, lie in preserving the rigidity of a wing which is made to telescope or reef, and in adjusting the equilibrium and controllability of a machine to alterations in sustaining surface. Neither difficulty, however, appears insurmountable; but expensive tests are necessary before the system can be effective, and lack of funds, for urgent research work, hinders progress. With variation of speed, and duplicate engine-plants, aircraft cease to be experimental; and sustained flight, in all weathers, becomes practicable. V. The first use of a commercial machine should be as a carrier of mailmatter. Recent demonstrations, while revealing the inability of existing aeroplanes to adhere to a rigid timeschedule, have indicated the rapidity with which aerial transit can be accomplished; and a mail-carrying aircraft, conveying express letters at special fees, and with the requisite dependability, should be an innovation of the not-far-distant future. When motorcars were in a crude stage, sceptics derided the prophecy that they would be employed, ultimately, in the postal service. The confusion of these critics, as the use of the motor mail-van grows, should teach them to be chary in decrying the possibilities of the air-mail. A definite field of utility, for reliable aircraft, should lie in carrying urgently consigned goods, at rates higher than those charged for land or sea transport. Here, again, the speed of the new method of conveyance must win its patronage. Further commercial uses, for weight-carrying machines, will be suggested by the experience gained in operating the first services. Then will come the era of passenger aircraft. Such machines in their initial application, may accommodate twenty or twenty-five people, and be capable of travelling several hundred miles, without alighting. Passengers will be business men, willing to pay high fares for the privilege of passing between the cities of Europe at speeds averaging 100 miles an hour. They will be seated in comfortable, totallyenclosed saloons; air travel, indeed, will have a smooth, vibrationless luxury unknown with present transit. Only the subdued hum from the powerplant in the fore-car, and the hissing rush of air past the polished hull, will indicate the huge speeds attained. Often earth or sea, faintly visible through the windows of the saloon, will be obscured by a film of low-lying clouds, and all sense of motion lost. To seek favorable wind conditions, aircraft will fly at altitudes of 10,000 feet, and higher, when upon long, highspeed voyages. It The first passenger aeroplanes will, naturally, be employed over routes upon which their advantages can be demonstrated most conclusively. should be the aim, for instance, to establish early services between London and Paris. By railway and steamer, this journey is one of approximately seven and three-quarter hours. It should be accomplished, by airway, in two-and-a-half hours; and travellers who patronize the new airroute will avoid delays in changing, and the much dreaded discomforts of the sea crossing. As to the actual operation of the airways, this much may be written, in prophecy. Below the London streets, in the era of practical flight, there will lie, probably, a central air-station. From it-north, south east, and west -will radiate mono-rail tube trains, conveying passengers and goods to the aerodromes, on the outskirts of the city, from which the chief aircraft services will be operated. • When the institution of a non-stop air service permits him to make the trip from London to Paris in a third of the time now required, a businessman will, before his journey, visit his The British Review. office as usual to deal with the morning's correspondence; then he will catch, say, the 11 A.M. air-mail, and arrive in Paris at 1.30 P.M. He will lunch, transact his business, and return by the 5 P.M. service, taking tea while in flight, and reaching London at 7.30 P.M., in reasonable time for dinner. From being a penance, in fact, this specific journey will become a pleasure. The world of commerce will, indeed, come one day to revere the names of those patient pioneers who, undaunted by difficulties or derision, laid the foundation stones of flight. From Paris to Berlin, or St. Petersburg, or Madrid, international flying routes will radiate; by degrees Europe, and finally the earth, will be linked by airway. Journeys which have occupied weeks, will be made in days; voyages which have lasted days, will be reduced to hours. The conquest of the air must, ultimately, prove man's greatest and most glorious triumph. A country becomes homogeneous, in thought and action, when its methods of communication are perfected; sporadic, merely wasteful effort is checked. What railways have done for nations, airways will do for the world. Claude Grahame-White. EVOLUTION IN HUMAN SOCIETY. The popular mind is slow to take up new ideas, but when it has once assimilated them, it holds them tenaciously. So it not unfrequently happens that the heresies of one age become the superstitions of the next; and notions which were at first received with scoffing incredulity, end by becoming dogmas which it is counted heterodox to question. This is pretty much what has happened in the case of the theory of evolution, or of what, in a vague way, may be called Darwinism. When first propounded, it aroused, in much the same way as did formerly the Copernican theory, the fiercest opposition; now, however, it has won such complete acceptance that it has entered, so to speak, into the very fibre of the thoughts and language of civilized man. Such phrases as "the struggle for existence," the "sur THE AIR: OUR FUTURE HIGHWAY. I. The world's demand is for quicker transport; but, by land and sea, travel has reached almost a limit of speed. To save only a minute, upon the timeschedule of an express train, has become a problem; and thousands of pounds in money, and thousands of tons of coal, must be expended upon attaining even a trifling increase in the speed of ocean liners. Yet the clamor grows; time, representing money, becomes more valuable day by day. Men chafe, on long journeys, even when in 60-mile-anhour dining-car trains; and there is a persistent cry, from the trading world, that mail services should be quicker, and transport of goods speeded up. Larger sums of money would be earned if people, letters, and merchandise were moved more rapidly. In meeting the demand for highspeed transit, lies the potentiality of a perfected aeroplane. Along the highway of the air-straight as an aircraft glides from point to point, ignoring such obstacles as are presented by mountains, forests, rivers, or seaswill go the high-speed traffic of the future. No permanent way need be built for the aeroplane; it makes its own. All an air-service needs is a chain of suitable landing-stations. Already, a pace of more than 100 miles an hour may be attained by monoplane; and this is but a beginning. Speeds appreciably greater should be possible with the large, powerfullyengined aircraft of the future. Having evolved passenger aeroplanes, with engines of 100 horse-power, which will average a speed of more than 70 miles an hour, designers are now planning to equip larger machines with motors developing 200 and 300 horse-power. Aircraft are being built to carry half a-dozen passengers as a normal load. Weighing several tons, they will fly at speeds greater than those of express trains. Machines even more ambitious, with motors of 500 horse-power, and a capacity for raising perhaps a dozen people, are in contemplation. Meanwhile, international committees are preparing to map out the "airways," along which traffic between nations will presently pass. They are considering, also, by what signs the new highways shall be indicated, either by day or night. But England, whose unpreparedness makes her apprehensive, passes laws to restrict the navigation of the air. Daily, although unrealized by the bulk of the people, the volume of skyborne traffic grows; so, too, does the number of airmen; and pupils, in hundreds, throng the flying schools. At one great aerodrome, nearly a thousand certificated airmen have already gone through their training. Cross-country flying is vastly on the increase. Aerodromes even in England-are being established in all directions. Slowly, but surely, the world is being prepared for a revolution in transit. II. A question which exercises the minds of ordinary folk is this: "Can flying be made safe?" Ninety-nine men out of a hundred, when speaking of the risks of aviation, conjure up a mental picture of an airman falling several thousand feet in his machine. The death of one man, in an aeroplane accident, affects the public more deeply than would, say, the killing of a number of people in a railway disaster. It is the terrible nature of a form of death, rather than statistics which can be adduced in connection with it, that leaves an impression upon the mind. Aerial transport presents an idea which is crudely new. Most of us, when we view it, find ourselves in the mental condition of a forefather whoupon some dreamer predicting a day when men would sit at dinner in a vehicle being drawn across country at 60-miles-an-hour-felt that his intelligence was insulted, and was properly scandalized. There is a mountain of conservative thought to be moved aside before to the eyes of the majority-the conquest of the air can be seen in its significance. As regards the dangers of aerial transit, what do statistics show? They tell us, for one thing that, with the purely experimental aircraft first induced to leave the ground, 35,000 miles were flown at a cost of three lives. The point, here, is this: were the navigation of the air so constantly perilous as is assumed, the earliest pioneers could not have attained such a mileage at so small a sacrifice of life. Since the summer, four years ago, when the world first realized that human flight was no longer a dream, the handling of aeroplanes has been rendered steadily safer; and now-thanks to the compilation of official statistics -it is definitely recorded that in France, during last year, only one life was lost for every 92,000 miles flown. But "But," objects the newspaper reader, "one sees accidents reported every day." That is true because, as was the case in the early days of motoring, the death of an aviator-provided he has a spectacular fall-is still news that papers print prominently. they do not tell readers, while chroni. cling occasional mishaps, that thousands of miles are being flown in safety by aeroplane, or that the army of airmen has grown from a handful until it now numbers several thousands. A false impression is thus created. Nine years ago, aeroplanes first began to fly; and, since then, more than two hundred men have lost their lives in disasters with aircraft of this type. But, remembering that an unknown and uncharted element was being invaded, by pioneers who had no experience and flimsy apparatus, such a death-roll, although deplorable, is not excessive at least, not when logically viewed. More than 100 people, it may be observed parenthetically, were killed last year while mountaineering. As a matter of fact, seeing that it has been passing through its perilous phase, and that many men have been over-bold, airmanship has shown that it is far from being so dangerous as is generally supposed. This is the point to be made: if, in the past, thousands of miles were flown without mishap, with experimental machines, and by unskilled men, we need not be apprehensive as to the future safety of flight, when aircraft are perfected, and their pilots experienced. The chief perils of aeroplaning, in early days, were the danger of some part of a machine breaking while in flight, or of a craft being overturned by wind-gusts. Nowadays, both risks have been sensibly reduced, and the former is being gradually eliminated. Wood and wire were employed, exclusively, in the framework of the first aeroplanes; but now essential parts are built of metal. Several all-steel machines have already been made, and have flown well. Flimsy craft, which might break under the impact of wind-gusts, are things of the past. The experience gained by aeroplane builders has shown them what "factor of safety" to provide. The parts of a modern-type aeroplane, upon which heavy stress is found to fall, are given a strength seven, ten, or twelve times as great as that required to meet the strains of normal flight. |