The Rise of the Flying Machine

The Birth of Aviation in the USA

In August 1889 Langley was in the midst of an exhaustive investigation into the aerodynamic properties and behaviour of thin flat planes moving through air at great speed.

The antecedents of Langley’s work go back to an original American enthusiast, named Israel Lancaster who, in his eagerness to discover the secrets of bird flight, had, in 1876 (another flagship year) gone to live in Southwest Florida and remained there for five years in order to watch “the sailing of the master soarers”, as Chanute described them.

In 1886, at a Buffalo meeting of the American Association of the Advancement of Science in Buffalo in New York state, Lancaster presented a paper on the “mechanics of soaring” which caught the attention of S. P. Langley, who was present at the meeting.

Lancaster held some original views, one of which was a theory that a soaring bird, or a man-made model patterned after it, could be made to advance against the wind through a mysterious force which he called “aspiration”. In fact this was nothing more than the thermals or ascending currents described by Pénaud, among others, and the real force that drove the soaring bird forward was gravity.

On hearing this, Langley’s “then dormant attention to the subject” (to use his own words) was aroused by Lancaster’s views and he determined to find out for himself what was or was not possible in the art of heavier-than-air flight.

In 1887, Langley started his experimental research and for that purpose he built an enormous turntable at Allegheny on which, over 3 years, he conducted a great number of experiments described in detail in his essay Experiments in Aerodynamics, published in 1891. In the course of his investigations he hit upon a theory which has been called “Langley’s Law”. This claimed (erroneously) that the faster a flying machine flew, the less power it would need or, in other words: “The force requisite to sustain inclined planes in horizontal motion diminishes instead of increasing when the velocity is augmented.”

One of the important conclusions from Langley’s experiments was again an incontrovertible proof that Newton’s sine-squared law was “widely erroneous” and that thin planes moving through air at small angles could support twenty times as much weight as Newton’s law had calculated. This had already been ascertained by Cayley, de Louvrié and others, but Langley produced scientific experimentally obtained proof of it.

Langley found that a plane loaded at 1 lb/sq ft would be balanced (meaning no vertical downwards pull) at a speed of 42 ft/sec which was 20% more than the 35 ft/sec that Cayley had calculated.

Langley also arrived at a mathematical blueprint for a plane of 10 sq ft surface flying at an angle of 2 degrees at 45 mph, claiming that it would support 209 lbs, with the expenditure of power of 1 hp.

This was of course pure theory because it presupposed a flying machine with wings of 10 sq ft weighing only 1,1 lbs including an engine of 2.5 hp (taking into account transmission losses and propeller efficiency) and Langley himself admitted this in a later (1901) edition of his essay. He had been carried away by his enthusiasm in extrapolating the lifting possibilities of a winged model at high speed instead of calculating from standstill, as he was to learn soon enough when he took up practical experiments.

Another important observation Langley made in 1889 during experiments with a device which he called a “plane dropper”, was that two wings of 15’ x 4’ placed in biplane form four inches apart so as not to interfere with each other, would double the sustaining force of a single such plane; a construction Langley did not himself use in his later experiments but which was not lost upon others. It is clear that in 1889 the biplane concept was born, a concept that, because of its strength and simplicity of construction, dominated aviation until the end of the 1920s.

In his conclusion Langley stated that his experiments did not yet prove that mechanical flight was possible because several practical problems had still to be solved. And to the solution of these practical problems Langley decided to devote the next few years of his life.

The second American member in Paris was Octave Chanute, who had been born there in 1832 but had gone to the US with his parents when he was six years old. After a distinguished career as an engineer specialising in railroads he began to investigate aeronautics in 1884 after he had retired from active business at the age of fifty-two. The last years of his life were then spent in actively promoting the cause of aviation.

Chanute travelled to Paris in 1889 to be present at the aeronautical congress and he read his first aeronautical paper there on 1 August. His French was not perfect, but it was fluent enough to establish an important link between French and American aviation enthusiasts. This was to prove a great boon to the aeronautical movement on both continents.

Chanute’s paper was about the resistance of air on inclined planes and, after sundry mathematical calculations, his conclusion was that fixed-wing gliding flight would require less energy than flapping-wing flight. This was not really a novel theory for the learned listeners, but it was nevertheless well received.

Chanute’s lecture was followed by one by Stephane Drzewiecki, a Russian engineer who covered the same ground as Chanute, although perhaps more thoroughly, and who, after analysing different birds tabulated according to size, weight and wing surface, had arrived at the conclusion that the problems related to human flight had been solved.

This tabulation was the interesting part of Drzewiecki’s paper. The tables were based on findings on sixty-four birds which had been measured, weighed and described with meticulous care by Mouillard in his book of 1881, previously referred to.

Drzewiecki’s tabulation, added to his demonstrations and conclusion, appealed strongly to Chanute, who lost no time in establishing contact with Mouillard as soon as he was back in Chicago. A correspondence with Mouillard ensued that lasted until Mouillard’s death in 1897 and was to have curious as well as far-reaching effects on aviation in America.

Otto Lilienthal

In 1889 a book was published by an eager German enthusiast. The author was Otto Lilienthal, born in 1848, and he heralded the entry of Germany into the field of aviation. Lilienthal, by his experiments with full-size man-carrying gliders up to his fatal final flight in 1896, was an early inductee into the International Air & Space Hall of Fame.

Germany had not at that time contributed much to the advancement of the science of flight, though an exception has to be made for Karl Friedrich Meerwein a century earlier. In 1781 he published an essay with the optimistic title Why should Man not be Born with the Possibility to achieve Flight? A prophetic figure, Meerwein, even before Cayley, had foreseen the possibility that man could emulate birds by means of a machine, as his intelligence and his status as Lord of creation entitled him.

“Why should a man be too heavy for flight?” asked Meerwein. He thought that it would only be necessary to construct a machine with wings large enough to carry his weight aloft. In order to achieve this project Meerwein suggested the use of two flat wings, pointed at the tips and with a high aspect ratio, and which could carry about 2 lbs/sq ft. This turned out not to be far removed from the realities of aerodynamics. The experiment required a courageous volunteer to be attached to the wing in a horizontal position and to flap his arms up and down, which Meerwein perceived as solving the problem. No consideration was given to taking-off or landing, and Meerwein was not very sure about man’s ability to move the wings with his musclepower alone, adding the sound advice that the first attempts should be made over water. He went so far as to build a glider himself, although he achieved no success. In 1784 he published a second pamphlet with the premonitory title: The Art of Flying after the Manner of the Birds.

A few years later Jacob Degen, another German fascinated by mechanics and a clockmaker by profession, built an ingenious machine shaped like a double umbrella which was moved by the force of his legs and arms. Degen was never able to achieve free flight, although a newspaper’s claim that he had done so inspired Sir George Cayley to write his famous 1809-1810 triple paper.

The title of Lilienthal’s book, Bird Flight as the Foundation of the Art of Flying (Der Vogelflug als Grundlage der Fliegekunst) was reminiscent of Meerwein’s 1784 essay The art of flying like birds (Die Kunst zu fliegen nach Art der Vögel).

In his book Lilienthal expounded his theory about flight and the means of achieving it, resulting from years of research and observation of live birds, of experiments with small models and of theoretical considerations. He also wrote about his visions of a Utopian future and included some poems exalting the ideal of flight and expressing the hope that man would soon emulate birds. His ideal was soaring flight as he had seen storks achieve in his native Pomerania.

The principal lesson Lilienthal had learned from the great soaring birds was the use of curved wings and he was convinced that this discovery, which he made in 1873, would open the way to the skies. He was not acquainted with the writings of Phillips and Goupil and he may be excused for thinking that his discovery was original because, as late as 1892, Hureau de Villeneuve, in an appraisal of Lilienthal’s book, was still convinced of the superiority of flat wings.

The book caused quite a stir and was eventually translated into English, but Lilienthal achieved fame because he did not limit himself to theoretical speculations, being one of the first to start practical experiments. The year after the publication of his book he built a full-sized glider that would carry him aloft and allow him to fly, in the manner that had been proposed by de La Landelle in his article about the “dirigible parachute” in 1884.

Lilienthal’s original idea was to fly by means of flapping wings, but as a preliminary he decided to try a fixed-wing soaring machine that was easier to build and simpler to handle. He thereby became the originator of the modern sport of hang-gliding.

During most of his experiments Otto Lilienthal was assisted by his younger brother Gustav and the pair prefigured the activities of the equally famous Wright brothers in the US. In both cases the older brother was the driving force who gave his life for his ideal and the younger brother devoted the remaining years of his life to the vindication of their vision.

The First Powered Experiments

As mentioned above, in 1888 Léon Serpollet invented, or rather dramatically improved, the flash steam generator which permitted the construction of a very light and powerful engine, the light powerplant that had hitherto eluded the aviation pioneers’ efforts.

A precursor in the use of power in a full-sized aeroplane was the Frenchman Clément Ader, who was continually on the brink of success but never quite achieved it.

Born in 1841, Ader was from early youth attracted to the mechanical sciences. He worked for a time on the railways and was continually thinking of new inventions. There is a certain inevitability about his becoming interested in human flight.

He built a flapping-wing machine in 1873, but then turned his attention to a new wonder of applied science, an electric machine that could transmit sounds over great distances. By 1880, the telephone had made him rich and famous, having in 1878 improved on the telephone invented by Alexander Graham Bell, and then in 1880 he established the telephone network in Paris. So, in 1881 he returned to aviation. Mouillard had just published his book and it made a deep impression on Ader, who decided to dedicate his efforts to the achievement of flight by means of a soaring machine moved by mechanical power.

In 1881 he travelled to Strasbourg so as to observe the storks there, and the following year he visited North Africa with the purpose of watching the great vultures.

His investigations showed him that the soaring birds always took off against the wind, as Lilienthal had also observed, and that the birds never left their nests when there was no wind.

Continuing his investigations, Ader became spellbound by the perfection of the bat’s wings and decided to use this animal as a prototype for his flying machines, in spite of its questionable aesthetic appeal.

Around 1889, he was working on the creation of his first mechanical bat which would be able to carry a man and would be powered by a steam engine fed by a Serpollet-type generator. His machine was to fly with fixed wings and was to be driven by a propeller moved by an extremely light and ingenious two-cylinder compound steam engine of about 20 hp.

Details of the progress of his construction are scant because Ader worked in secrecy, having in mind the importance of his plans for national defence. Such secrecy does not help the historian who is trying to assess what was real and what was imaginary in the flight or flights Ader claimed to have made. During the next decade he spent a fortune on the construction and perfection of several flying machines. This will be related in a later chapter.

Another pioneer of mechanical flight was Hiram Maxim, who decided in 1889 to create a real-life or rather a larger-than-life flying machine, regardless of cost and effort. Born in 1840 in the US, Hiram Stevens Maxim made a fortune from several inventions, the most noteworthy being the lethal machine-gun which was to cause so many casualties during the First World War.

It was inevitable that Maxim was also to become attracted to human flight and in Great Britain, where he lived from 1881, Maxim began to study aviation in earnest in 1887. Maxim, who was sure of his own capabilities, said that he could solve the problem in five years if he was allowed to spend £100,000 ($500,000). The money, or a great part of it, was indeed spent but, although Maxim did become a true expert on aviation, he did not reach the definitive solution.

His plan was to dedicate three years to perfecting a suitable internal combustion engine along the lines of the system invented by Brayton or by Otto, but as neither type was at that moment adaptable as an aviation powerplant he did not go ahead with his plan. Meanwhile the technique of drawing steel tubes had become so perfected that it had become possible to build them with such a small inner diameter that, when heated, the water inside evaporated instantly.

This system was perfected by Serpollet in the flash steam generator, so Maxim, like Ader, was forced to turn to steam power for the great aeroplane flying machine he had in mind.

Maxim had already carried out experiments with a whirling arm and a wind tunnel, and in 1889 he decided to leave speculation and small-scale experiments and get down to the realization of man’s age-old dream. He applied for two master patents; then he engaged two first-rate craftsmen from the US and began the construction of a huge flying machine on his property of Baldwyn Park in Kent, in order, as he stated, to experiment with a real aeroplane instead of continuing to elaborate theories, as most of his predecessors had done. It was soon possible to evaluate the results he obtained.

The year 1889 was also remarkable for the great number of experiments with piston internal combustion engines as well as those driven by steam.

Daimler and Maybach, who had conceived the light internal combustion engine seven years before, built a V-twin cylinder engine during 1889. In this engine two pistons worked on a single crankshaft by means of forked connecting rods and this may be considered as the ancestor of the great number of V-8 and V-12 engines that were to be built thereafter.

Meanwhile progress was being made in the use of air compressed at very high pressure as a source of power. The development of the automobile torpedo for the Austrian Navy by Whitehead in Fiume had called for a compact and powerful prime mover and the firm of Peter Brotherhood Ltd. in London had designed and developed a successful three-cylinder radial engine, the Brotherhood engine, driven by compressed air from a separated container.

At the same time in Australia, Lawrence Hargrave, who was then experimenting with small flapping-wing planes, was on the lookout for a more suitable source of power than Pénaud’s system of twisted india rubber which Hargrave had used until 1889, when his last flapping-wing model was made.

In 1887 Hargrave wrote to London inquiring about engines suitable for experiments with model aeroplanes but received no reply until, at the end of that year, a Major of the Royal Engineers, who was stationed in Sydney, provided him with details about Brotherhood’s radial torpedo engine. So in 1888, Hargrave built the first of thirty-six aero engines of different types which he was to manufacture during his aeronautical experiments. The first was a single-cylinder engine moved by compressed air.

Then, in 1889, Hargrave built a three-cylinder radial engine after the Brotherhood pattern but with the peculiarity that its crankshaft was fixed and the cylinders revolved around it. The cylinders were attached to the blades of a propeller and thus the first rotary aero engine came into being. It started Hargrave on the road to research into fixed-wing propeller-driven aircraft, as he had already become acquainted with previous experiments along those lines, and also with Pénaud’s writings, and probably with Cayley’s as well.

During 1889, ideas around internal combustion engine construction for airships or aircraft were running wild in France. It all started with Fernand Forest, who had published a drawing in 1888 of an air-cooled engine which had thirty-two cylinders arranged radially around a four-throw crankshaft. Designed for 120 hp, nothing tangible ever came of it except fame for Forest later on. And in 1889 Count de Dion applied for two patents for internal combustion engines, one was a three-cylinder rotary and the other a big ten-cylinder radial with many original features.4 This flurry of activity was to lead to the creation of the first real aviation engines about ten years later.

The important pioneers of the following decade had started with their specific activities by 1889. Many of them were still around with advice and counsel when the era of real flying began, but at the turn of the century the heavier-than-air flying machine had not yet found its definitive shape, nor was there a clear-cut solution in sight.

4. Automobile Quarterly Vol. 15, No. 8, pp. 286-289.

Clément Ader

Comparing the different attempts to fly full-sized machines during the 1890s, it appears that the results were inversely related to the sums of money spent on them. Two very expensive endeavours to develop a powered flying machine failed without showing any practical result nor leading to further development, or even influencing anybody.

The first flying machine ever to be built was that of Clément Ader, the “Eole”. It was being readied at the end of 1889 after years spent on design, experiments on a small scale, actual construction and preliminary tests.

The “Eole” was said to have a wing surface of about 300 sq ft, a total weight of 650 lbs and was powered by a steam engine developing 20 hp. If these figures are correct, the wing loading amounted to 2.4 lbs/sq ft and the power loading to 32.5 lbs/hp, which was sensational for that time.

Sir George Cayley had calculated that a winged machine loaded at 1 lb/sq ft would become airborne at a speed of 35 ft/sec. (about 25 mph). The higher wing loading of the “Eole” must have raised take-off speed to over 30 mph. “Eole” did not use any form of assisted take-off, but ran over level ground under its own power in the modern manner. But it is impossible to know whether an acceleration from zero to 30 mph was ever achieved.

Only patent drawings of the original “Eole” remain. It is a marvel of engineering which fills us with amazement. The tricks and devices used in order to obtain lightness from the materials employed — including bamboo, wood and steel tubes — verge on the incredible and it is a pity that so much ingenuity did not lead to more positive results. Modern attempts to recreate and evaluate the craft have met with mixed results. A full-size replica built in 1990 at the École Centrale Paris crashed on its first flight, injuring its pilot and leading to the termination of the experiment. Scale models, however, have been successfully flown.

Ader invested a small fortune in building the “Eole”. He is said to have spent the around $120,000 on his aeronautical activities up to 1891.

The first tests were made on the grounds of the property of Madame Isaac Péreire at Armainvilliers, near Paris. The Péreires were a family of bankers and Ader had been associated with them during his work in developing the telephone.

The “Eole” was brought to Armainvilliers in a special covered cart for secrecy. A strip of about 600 yards was prepared and a few tests were supposedly held during the autumn of 1890. But it is not certain whether these tests ever took place at that time and still less if they were successful. Ader himself later claimed to have become airborne over a short distance (50 metres or 165 ft) on 9 October 1890.

Nobody was present at that flight except Ader’s two closest assistants. Everybody living on the property had been asked to keep away, even, according to one source, the lady of the manor, which seems hardly credible.

For want of official witnesses, these were replaced by a few lumps of coal which were buried at the precise place of the alleged take-off by Ader’s assistants. The most amazing part of this story is that these lumps of coal were dug up 47 years later, which is remarkable in itself.

Ader himself did not reveal these flights until 1906 so that in 1890 the feat was a complete secret. But when more information was wanted later on about this undoubtedly important event, a gardener was found who, in spite of the interdiction, had hidden in a bush with some other men to observe the experiment. In 1908 this gardener claimed to have seen Ader in his “Eole” climb to 50 cm height (20 inches) and fly over a distance of 10 ft, which is a very short jump indeed. But no definite proof of that 1890 flight exists unless one is willing to accept the silent testimony of a few lumps of coal.

It would have been difficult to keep an event of such importance completely secret and something did filter through to the Paris press during the summer of 1891, which is probably the time when these tests were started, rather than in 1890. On 20 June L’Illustration mentioned secret trials and despatched a reporter who saw “an enormous bird of bluish hue” and who was also able to draw a sketch showing a flying mechanical bat on skids but this may have been a misinterpretation.

Ader himself gave interviews to several newspapers, notably to Le Temps of 9 July 1891, in which he did not mention any previous flights but told the story of his earlier studies that had led to the construction of “Eole”, which was supposed to be being tested around that time. He stated that “the problem was an exceedingly difficult one, involving enormous mechanical difficulties which increase rapidly with the size of the apparatus”. The “Eole” was described in La Revue de l’Aéronautique during 1893.

After the uproar in the press during the summer of 1891, Ader showed the “Eole” in a pavilion belonging to the city of Paris where it was inspected by the Minister of War, Charles de Freycinet; though it is strange that no photograph of the aeroplane was taken on that occasion.

De Freycinet was interested and Ader was allowed to move his aircraft to the military camp of Satory for further tests and for evaluation as to its possible military usefulness. Ader also claimed to have flown the “Eole” at the Satory camp, but very soon after its arrival in September 1891, it deviated from its course during one of the test runs and struck a pile of material that had served to prepare the test area and when the officer despatched to inspect Ader’s “Eole” arrived, he found nothing but a wreck.

Having spent much of his fortune on aeronautical experiments, Ader could have become dispirited but he seems to have possessed that indestructible faith in his own vision that marks so many outstanding personalities.

He was able to convince the officials of the War Ministry and on 3 February 1892 a contract was signed with the French State which accorded Ader a payment of 300,000 francs ($60,000) for the construction of a new aeroplane. He was also promised the return, by an act of Parliament, of the 600,000 Frs he had already spent, plus an additional sum of a million francs in return for the relinquishment by Ader and his heirs of all rights over his invention.

This contract sounds highly irrational because Ader bound himself by its terms to build an aeroplane able to carry a pilot and a passenger or the equivalent weight (75 kg) in explosives, as well as enough fuel and water for a flight of six hours at 34 mph with the ability to reach an altitude of 1,000 ft. These were daunting requirements for a man who had just built a machine that was barely able (if at all) to lift itself over a few feet with just the inventor on board. Ader must have been either a determined optimist or desperate for money.

Once the contract was signed, Ader started work on a second single-engined aeroplane but meanwhile he calculated that in order to comply with the clauses of the contract he would have to build a bigger aeroplane carrying two engines, each driving a propeller.

The authorities in charge agreed with his new proposals and in July 1894 an additional sum of 250,000 Frs ($50,000) was granted. These two large sums did not come from government funds but were part of a legacy made by Giffard to the French State, perhaps with the proviso that a part or the whole of the legacy was to be expended on the construction of an aerial machine.

It should be recalled here that Ader received the money that Pénaud had hoped to obtain for furthering his own experiments and when this hope was thwarted it led to Pénaud’s suicide, followed by that of Giffard.

The “Avion III”, as the new aeroplane was to be called, closely followed the pattern of the “Eole” in that it was another tailless bat-winged machine but it was bigger, having a wing surface of 430 sq ft at their maximum extension and when finished it weighed about 400 kg (880 lbs). Its two steam engines produced a total output of at least 40 hp (some sources claim 60 hp) so that, with a wing loading of 2 lbs/sq ft and a power loading of less than 20 lbs per hp it was a great advance over the already extraordinary specifications of the “Eole”, and Ader may well have believed that he would be able to comply with the clauses of the contract.

A big building lot was acquired and a complete aeronautical factory was built. Twenty-three men were engaged and work progressed during four years, the first time that so much money had been spent on an aeroplane.

The construction probably took more time than had originally been estimated but in 1897 the “Avion III” was ready to Ader’s satisfaction. The extremely light steam engines functioned and the wings were submitted to a static loading test corresponding to the weight of the machine. When Ader informed the War Ministry of the completion of the aeroplane a committee was appointed, consisting of three generals and three learned professors, all with excellent credentials and headed by General Mensier as president of the committee.

After inspection at the workshops, the “Avion” was moved to the manoeuvring grounds of Satory where, under the supervision of Lieuteneant Binet, a testing ground was prepared, consisting of a circular area 120 ft wide and with a diameter of 1,500 ft.

The expediency of selecting a circular testing ground may be questioned but Ader probably wanted to test his aeroplane on calm days and a ring form takes less space than a square or rectangular area.

A first test was held on the 12th October in the presence of General Mensier. Ader had to wait until sunset for the wind to drop and he started on his first trial run at 5.25 pm. With the machine running at around 12 mph, Ader, by means of a steerable rear wheel, was able to follow the chalk line which ran down the middle of the circular track and, having made a complete circuit, he stopped at his point of departure.

This was considered a success, so a trial flight was arranged for two days later, on 14 October. This time General Mensier was accompanied by General Grillion, another member of the Committee, with Lieutenant Binet, who had been in charge of the preparation of the testing ground, was also present. According to the official report drawn up on 21 October by General Mensier, there was a fairly strong and gusty wind blowing from the south.

It is to be wondered why Ader, after all the time and money spent on this project, did not insist on waiting for a calm day, as the report states that Ader had explained the danger of gusts of wind to the generals. Anyway, towards sunset the wind appeared to die down and it is possible that the generals did not want to postpone the trial for another day.