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mized in aircraft research. Only individuals in any army, navy or populace appreciated it. Its exponents were a butt for attack.

Still it was war or the fear of war that was responsible for what there was. War has often been the great inciter of technical advances it accounted for the Roman roads and for the modern steel industry when battleship plates were founded and forged. Such industries have in the past made some compensation to the world for their malignant first inspiration. So, too, will aircraft in its civilian uses and in many indirect ways.

The exact calculation of stresses, the exact adaptation of ma- terial to meet them, the most radical economy of avoidable weight, all of which are in the essence of engineering progress, have been enforced upon the new engineer physicist of aerial science, and young and brilliant aircraft engineers have, since the Armis- tice, been thrown into industry generally, imbued with the exact- itude and thrift of mechanical material learnt under the grave penalty attaching to small errors in strength, weight or quality or design for aircraft construction.

The introduction of the scientific idea was an intense uphill struggle. Flying was first in the hands of men of enthusiasm rather than of precision; the pioneers were more courageous than scientific or critical. Dynamic similarity, the theorem of three moments and the like were uninteresting to the small makers, and all makers were in a small way. The data for the calculation of aeroplane stresses were insufficient to move the larger firms to quit the imitative methods of design which were the beginnings of the industry. The risks from obvious misadventures, from fliers' errors, from bad landing-grounds, etc., were so great that the hazards to be guarded against by calculations and wind- tunnel experiments appeared few and negligible by comparison.

Before the war public pressure had a rather doubtful directing influence. If it was not explicitly said that such appliances must be frail and dangerous, it was assumed. In one country after another the ministers were rather upbraided by the air industry and dismissed eventually for failing to spread themselves on large orders than urged to develop the basis for strength and balance, by expenditure now proved justifiable on precise calculations, labo- ratory work and mathematics, finer metallurgy, woodcraft and chemistry, instruments and navigation such as are recorded in the succeeding sections.

The main efforts made on the scientific side have been individ- ual, and for those individuals are mainly unrequited. Many are dead scarcely heard of E. T. Busk; K. Lucas; R. M. Groves; B. Hopkinson; Pilgrim; Pinsent; Usborne; many others lived on in 1921 to see the result of their work, which was unparalleled in brilliance of achievement. Fortunately the names of the per- formers of heroic flights live on, and many unavoidably there are omissions from so great a list appear in Section I.

In 1911-2 the compelling necessity for providing in the inter- ests of fliers a margin of strength for aircraft, calculated upon the stresses induced by its speed and by its manoeuvres, was first accepted. So far as we know, this importation of an engineer- ing standard was British, and was imposed upon foreign sup- pliers for the first time. '

The various nations, each wanting to know how the other was getting on, would purchase a few examples abroad; a proceeding naturally coupled with any known precautions for the home flier whose person would be risked in testing them. In any coun- try the industrials regarded foreign purchases with some jealousy, since a tenuous air vote was seen to be expended elsewhere than with the home constructor; still an informative exchange of tech- nical knowledge ensued.

The 20 H.P. engine of Wright and the 35 H.P. engine of Green were seen to be too small by any who knew the 50 H.P. Gnome in flight. The speedy monoplane of Nieuport (French 1910) showed Britain the value of smooth external lines for the craft. The Wright biplane (U.S.A.) bore only 2 Ib. per sq. ft. of wing area, and Farman followed its lead in France. The uses of heavy loading, as in the De Haviland craft, appeared later, when its demerits were envisaged and difficulties, such as the high speed of alighting, overcome simply by the great skill and courage of fliers. The German Zeppelin taught much to Britain. The

British Avro and BE2 taught the possibility of a wide speed range to the French and others, and generally aircraft lore became international. (M. O'G.)

I. PERFORMANCE OF AEROPLANES, 1909-1920

The Arena of Aeronautics in igog. The achievements in 1909 had been latent in the effort of the previous 40 years; that which appeared sudden was the outcome of protracted experiment and the driving force of great personalities. The date recalls the names of Wright, Voisin and Farman. The year 1908 had made power-driven flight a reality. Farman had flown from Chalons to Reims; Orville Wright had flown for over an hour in America; Wilbur Wright held the Michelin Cup with a flight of 124 km. in France.

In 1909 man little knew at what bitter cost he would maintain the conquest of the air; yet the toll of life served but as a stimulus. The International Conference that was held in London consoli- dated the position of the Aero Clubs of the various countries with a view to the advancement of aeronautics as an organized move- ment. The great natural flying-ground at Pau soon made it the Mecca of aeronautics. There Wilbur Wright created the first flying-school, and among his pupils were names now famous. At the aero show in London the public inspected and handled ma- chines that really flew. At Farnborough, Cody was experimenting with a machine that was to glide down a wire. Bleriot, who had emerged from crash after crash unscathed, flew from Etampes to Orleans, 25 miles. His little machine hopped over hedges and trees, its diminutive engine humming above the roar of the Paris- Orleans express, the windows of which were white with faces upturned to see the new wonder. On a memorable Sunday morning (July 25 1909), Bleriot set out from France without a watch or compass to fly the Channel; his monoplane was lost in the haze; but he emerged triumphant towards the cliffs of Dover, where he landed on a slope and crashed. His feat eclipses all others of the year, and is the forerunner of the cross- ing of the Atlantic 10 years later. The analogy goes further, for Hawker's failure to cross the Atlantic is reminiscent of that other failure of Latham's to wrest the prize from Bleriot.

The year is memorable for flying meetings which roused public enthusiasm in many countries: at Reims, Brescia, Berlin, Co- logne, Blackpool and Doncaster. At Reims Latham covered 96 m., while later in the year Paulhan climbed to 600 metres, a dizzy height in those days. The Comte de Lambert, a pupil of Wright, flew from Juvisy round the Eiffel Tower and back, the first flight over a town. In Germany Herr Grade won a 2,000 prize for the first German to fly a figure of eight round two posts placed i km. apart. At the close of the year Farman held the Michelin Cup with a fine flight of 234 km., made at Chalons.

The Flying Qualities of the Early Aeroplanes. So rapid has been their development that it is worth recalling what these early aeroplanes were like. The factors which govern the balance of an aeroplane and the respective functions of the movable and fixed surfaces used for its control during flight were, in 1909, ill understood. The probable, possible and impossible were all one. Aeroplanes were built by eye and developed by trial and error; the light aero engine was in its infancy. Wilbur Wright laid the foundation of aeroplane control as we now conceive it, but ham- pered it by combining the movement of the vertical rudder with the warping of the main planes for turning in the air. The pio- neers flew almost by blind instinct; they had but the vaguest idea of how to remedy a loss of control; some were even inclined to doubt that remedies existed; atmospheric disturbances and so- called " air pockets " were referred to with awe; instruments which now assist the maintenance of balance, attitude and flying speed were unknown, and when suggested were objected to; it was all that human concentration could do to make proper use of the control surfaces to maintain equilibrium, not only because the equilibrium was essentially of an unstable kind, but because the control surfaces themselves were often incorrectly designed and thus treacherous or inadequate. It was on such machines that the early pioneers committed themselves to the air, break- ing records over laud and sea.