E. Charles Vivian

The balloon was but a year old when the brothers Robert, in 1784 attempted propulsion of an aerial vehicle by hand-power, and succeeded, to a certain extent, since they were able to make progress when there was only a slight wind to counteract their work. But, as may be easily understood, the manual power provided gave but a very slow speed, and in any wind it all the would-be airship became an uncontrolled balloon.

There are few outstanding events in the development of aeronautics between Stringfellow's final achievement and the work of such men as Lilienthal, Pilcher, Montgomery, and their kind; in spite of this, the later middle decades of the nineteenth century witnessed a considerable amount of spade work both in England and in France, the two countries which led in the way in aeronautical development until Lilienthal gave honour to Germany, and Langley and Montgomery paved the way for the Wright Brothers in America.

The end of the War brought a pause in which the multitude of aircraft constructors found themselves faced with the possible complete stagnation of the industry, since military activities no longer demanded their services and the prospects of commercial flying were virtually nil. That great factor in commercial success, cost of plant and upkeep, had received no consideration whatever in the War period, for armies do not count cost.

An offshoot from the vertical type, doubling the power of this with only a very slight - if any - increase in the length of crankshaft, the Vee or diagonal type of aero engine leaped to success through the insistent demand for greater power. Although the design came after that of the vertical engine, by 1910, according to Critchley's list of aero engines, there were more Vee type engines being made than any other type, twenty-five sizes being given in the list, with an average rating of 57.4 brake horse-power.

Until the Wright Brothers definitely solved the problem of flight and virtually gave the aeroplane its present place in aeronautics, there were three definite schools of experiment.

Into the later months of 1919 comes the flight by Captain Ross-Smith from England to Australia and the attempt to make the Cape to Cairo voyage by air. The Australian Government had offered a prize of L10,000 for the first flight from England to Australia in a British machine, the flight to be accomplished in 720 consecutive hours. Ross-Smith, with his brother, Lieut.

BY LIEUT.-COL. W. LOCKWOOD MARSH

The very first successful design of internal combustion aero engine made was that of Charles Manly, who built a five-cylinder radial engine in 1901 for use with Langley's 'aerodrome,' as the latter inventor decided to call what has since become known as the aeroplane.

There was never a more enthusiastic and consistent student of the problems of flight than Otto Lilienthal, who was born in 1848 at Anklam, Pomerania, and even from his early school-days dreamed and planned the conquest of the air. His practical experiments began when, at the age of thirteen, he and his brother Gustav made wings consisting of wooden framework covered with linen, which Otto attached to his arms, and then ran downhill flapping them.

Although the first actual flight of an aeroplane was made by the Wrights on December 17th 1903, it is necessary, in considering the progress of design between that period and the present day, to go back to the earlier days of their experiments with 'gliders,' which show the alterations in design made by them in their step-bystep progress to a flying machine proper, and give a clear idea of the stage at which they had arrived in the art of aeroplane design at the time of their first flights.