summary of the exhibition-script
"From the crest of the hill the great bird will take his first flight, filling the universe with wonder, all chronicles with his fame. And eternal glory be to the place he was born." - Leonardo da Vinci 1497
"... If driven by yearning, like we are in flight
To glide away in the realm of the height, Enjoying what flying can bring - Then see our wings and measure our powers And study the lift, which force is ours, Concluding the works of our wing. Then seek that which carries us there Whilst our pinions gently stroke the air Whilst our flight goes on, ever untiring! That which was bestowed by a gracious creation May lead you then to the due realisation And solve the enigma of flying. O! Just apply the power of thought: An eternal ban must not be wrought - Also you will be borne by the ether. It cannot be your Creator's will To doom you, the first He made, to earth until Eternity, to refuse you flight for ever." - Otto Lilienthal, 1889, from "Der Vogelflug" ("The flight of birds"): "one can almost hear the stork trying to persuade us ..."
"Thus the aeroplane, the tool of aviation, confronts man with all the ancient puzzles of the world and becomes for us the tool of recognition and of self-recognition." - Antoine de Saint-Exupéry 1939
"They wore skins. Made fire with stones. They forged iron and built castles. Printed books, harnessed steam, tamed lightning, became mobile. They discovered the atom and conquered the moon. But it was one of their greatest dreams that people accomplished just a short time ago: free flight. - To spread the wings, to start running, to glide, to float, to fly. To circle in the upcurrent. Soundless, almost powerless. It is the fulfilment of a never-ending yearning." W. Pfändler, Drachenflieger-Magazin, 1987
"We may assume that the balloon was not actually conducive to the art of free flight, if one does not want to go as far as regarding the air balloon as a virtual impediment to the free development of aviation technology, because it divided interests and directed such research which should have been serving free flight, onto a wrong flight path." - Otto Lilienthal Otto Lilienthal, 1888
"Columbus opened up a new continent, the Montgolfiers have opened up the sky." With these words the first balloon flights were celebrated in 1783. The enthusiasm flew away when it proved impossible in the next one hundred years to make the balloon steerable. It remained at the mercy of the wind.
"During one of these trials the floating against
the wind lasted longer, which made us let go of the lines. The kite then
flew against the wind without falling. We returned home from this trial,
which took place in September 1874 ..., convinced that gliding is not
just for the birds, but ... that man, too, can artificially create this
kind of flight, which requires only skilful steering and no powerful moving
of the wings." - Otto Lilienthal
There are ancient technical developments which in the broadest sense have something to do with flying. These include the arrow with its stabilizing feathers, the boomerang, the windmill, and the kite. This flying apparatus has always been more than an autumnal pleasure for children.
"We must therefore conclude that the one and only possibility which can be used for an efficient flight by man is the exact imitation of bird flight in terms of aerodynamic features, because it is most probably the only method which allows flight that is free, fast and which at the same time requires little effort." - Otto Lilienthal
For thousands of years the bird was the model for the realization of human flight. The "bird-man" influenced the artistic imagination just as much as the aeronautical pioneer spirit. Bird flight is still the object of ornithological research and a model for solving technical problems. The human chest muscles are, however, far too weak to manage wings as a bird does. Icarus' flight is a legend. The recently developed muscle-driven flying machines use human leg power.
"Daedalus and Icarus", German wood-cut, 1497.
The wings of a bat consist of soft membranes, skins which are stretched across rigid fingers. For mainly practical reasons Lilienthal and others adopted this construction, which was easy to realize technically and to fold away.
Experiments in the technical implementation of wing flapping, Schmidt 1965: graph of the degree of efficiency against the wing stroke rate.
"The content of my work shows so much that is new and which deviates from the normal assumptions and notions that ... I did not publish the results I had found until the whole material could be given in a complete form and, in my opinion, the logical consistency of the one result could proceed from the other." Lilienthal's first aircraft construction was a result of 23 years of aeronautical experiments. His investigations had a fascinatingly simple structure, precise exposition and systematic approach. His book was mechanics that everybody could understand, and contained in addition a water colour, a poem and eighty woodcuts by the author. It became the most important theoretical publication on flight of the 19th century. In 1889 Lilienthal finished his studies of flight theory with the publication of his book. Even when the Wright brothers inaugurated the era of powered flight, it was still "the best thing in print". Lilienthal's methods of evaluating wing measurements are still used in the same way today: his polar diagram.
On the initiative of the War Ministry, a "Commission to draw up a Programme for Experiments with the Objective of ascertaining the Laws of Air Resistance with regard to the Production of Steerable Aircraft now being used" was set up in November 1867 under the chairmanship of the Berlin professor of physics, Gustav Magnus. After his death, Franz Reuleaux, the director of the Berlin Trade Academy (the predecessor of the present Technical University), took over the leadership and offered his student Otto Lilienthal a post as assistant, which was however turned down. Later Hermann von Helmholtz became chairman.
Apparatus for determining the laws of air resistance made by Prof Schellbach (member of the Commission), J. G. Halske (joint owner of the telegraph company Siemens and Halske) and Professor Förster (director of the Berlin Observatory). Results are not known.
Hermann von Helmholtz (1821-1894), physician, physiologist and physicist, whose studies pointed the way in many fields.
Franz Reuleaux (1829-1905), the founder of scientific kinematics.
Aerial forces 6
Although the problem of flow resistance was known from ballistics and ship construction, Lilienthal's measurements of "lifting air resistance" were the first measurements of lift force to be actually available. In long series of measurements, numerous wing areas were investigated in still and moving air. Through the simultaneous registration of the lift and the resistance, these were the first actual measurements of wing profiles. The rotation experiments in still air were checked in real wind conditions. The so-called whirling arm device was originally used to check cannon balls and windmill sails. In various designs, it was also Lilienthal's main testing device.
Numerous studies of lift and resistance, aeromechanics and flight stability, which pointed the way for others, were made by the English scholar Sir George Cayley (1773-1857). His work, however, did not receive the attention due to it. It was especially the relationship between shape and aerial forces which long remained uninvestigated in aeronautics. Measurements of aerial force gained greatly in precision when artificial air currents (wind tunnels) were used. Sketch for a whirling arm device from Cayley's notebook The builder of the Parisian tower named after him, Gustave Eiffel (1832-1923), carried out, by means of a recording device falling from the platform, what were probably the most careful and precise measurements of air resistance before the utilization of wind tunnels.
Woodcut from his book Device built by Lilienthal for measuring wind speed. Reproduction
Reproduction of one of Lilenthal's whirling arm devices
Experimental set-up for measurements in wind. Drawings from the book "Der Vogelflug" - "The flight of birds"
Wind tunnel, 1931, Aerological Observatory near Lindenberg, property of the museum.
"The construction of usable flying devices is not under all circumstances dependent on the availability of powerful and lightweight engines." With the notion of initially learning step-by-step to glide without a motor, Lilienthal found what was probably the only possible route to the aeroplane. His method was later referred to and continued with the words "From the step to the jump, from the jump to the flight". It also made motorized flight possible. At the end of his book on bird flight, Lilienthal listed fundamentals for the construction of a man-carrying flying apparatus. Point 13 describes the necessity of wing curvature.
Numerous contemporaries considered the motorized generation of the required lift to be the main problem of human flight. In 1893 the Russian naval officer Mozhaysky built a motor aeroplane after measuring aerial force and experimenting with models and kites. Nothing is known about experiments with this machine, which presumably did not fly. In 1894 the English arms manufacturer Maxim constructed a huge flying machine of 3.6 tonnes after expensive aerodynamic experiments. But no theoretical or practical attempt was made to learn to master flight situations. In 1903 the American physicist Langley constructed the first aeroplane with a gasoline engine. It crashed after 30 metres. In the history of aviation there have been countless other unconfirmed successful "first" motor flights; it is however not certain that these could be repeated.
Lilienthal's corrections in the first edition.
Wing profiles investigated by Lilienthal. Hiram Stevens Maxim (1840-1916) Maxim's flying machine with a 360 h.p. engine
Lilienthal's draft of an "artificial take-off station" for the step-by-step learning to fly safely. These plans were used, on a reduced scale, for the construction of the still-existent "Fliegeberg", an artificial hill in Lichterfelde, Berlin.
Construction forms 8
The "Derwitz Apparatus" of 1891 was the first successful flying machine in history. The construction form still reminds one of the original drafts for a man-carrying apparatus in Lilienthal's book on bird flight, adapted from the stork and the gull. The flying apparatus consisted of two wings in the shape of bird feathers, whose quills were screwed together at an obtuse angle. He retained the resulting spar cross in later constructions. It is the characteristic "cockpit" of all Lilienthal gliders. The apparatus was reduced in size during the experiments. Lilienthal managed flight distances of up to 25 metres.
Wing span: 7.6 (later 5.5) m Wing surface: 10 (later 7.8) sq m Wing curvature: 1/10 of depth
reconstruction, 1988 in the original (larger) form
The standard gliding apparatus began to appear from 1894 in a series of intermediate stages. From 1893 onwards, Lilienthal built his flying apparatuses in a form resembling a bat and which was easy to fold away. The curvature of the wings was adjusted by means of inserted "profile rails". At least nine devices were built, eight of which were sold. There are still originals in London, Moscow, (Munich) and Washington.
Wing span: 6.7; wing surface: 13.6 sq m; reconstruction in 1925, restoration in 1983; recent reconstructions in 1983 and 1991.
Reconstruction folded away for transportation, weight c. 15 kg, width 2 m
Model 1:5 built by Paul Beylich, mechanic in Lilienthal's machine factory and assistant at the flying trials
The experimental device of 1895 (wing slat apparatus) was used to test several systems to improve aeromechanics. What first strikes the eye is the so-called wing slat. In addition, a twist control and resistance surfaces were tested. Tests were made to improve the flying machine, which had no inherent stability, by means of additional active control components, but the experiment must be characterized as a failure. Only after inherently stable flight had been achieved did the pilot have the room needed for steering manoeuvres.
Wing span: 8.8 m Wing surface 19 sq m Reconstruction 1:1, 1989
The "great double-decker" was a result of adding a second wing taken from the "standard gliding apparatus". A "small double-decker" was built and flown on the basis of the smaller "storm wing model". The resulting downwards shift of the centre of gravity and the reduction in wing span, despite large wing area, made the double-decker easy to steer.
Wing span: 6.7 + 6.3 m Wing surface: 13.6 + 10.4 sq m Reconstruction 1:1, 1983 and 1989
Flight with small double-decker, October 1885 on Lilienthal's "Fliegeberg" in Berlin
Wing stroke 10
For a long time many inventors regarded the beating wing as a prerequisite for bird flight. Only when they started looking away from this principle were they successful. Nevertheless, the bird's wing is a highly flexible organ of movement and steering. The bird constantly changes the shape and position of its wings and always flies with "optimum aerodynamics". Not even today can any technical system steer in such a complex way. All his life Lilienthal was interested in wing strokes. He designed various experimental devices to work out the "lifting air resistance" (as Lilienthal correctly called lift) of flapped wings.
With the "cycloid device", Lilienthal restarted basic measurements of wing stroke drives, after he had already started flying successfully. Functioning model. Lilienthal tested the knowledge he had gained on two different constructions of ornithopter (a flying machine with flapping wing drive). He was concerned first with gilding over longer distances. These drives could be powered both by muscle-power and carbon dioxide motors that he had constructed.
The "Altwigshagen device", 1868, for testing wing strokes with valve-shaped flapping wings moved by a pedalling mechanism, drawing by Lilienthal
Altwigshagen device, flapping and pedalling mechanism, reconstruction 1989
Experimental device for measuring the "increase in air resistance by flapping movements", reconstruction 1991
Small ornithopter, 1893-1896, reconstruction 1989
Carbon dioxide motor for driving the ornithopter, 1893, reconstruction 1990
For Lilienthal his man-carrying flying machines were experimental devices. They were repaired and modified in the course of the flight trials. There are photographs of eleven different constructions and ideas or designs of several other gliders. In museums worldwide only two originals of these constructions are still in existence. The replicas and reconstructions, especially of the machines that have been lost, require not only the use of appropriate materials but also an understanding of Lilienthal's techniques and procedures.
In 1925 the town of Anklam commissioned the copying of a standard flying machine, using original parts. The constructor of the model was the Berlin artist Hans Richter, who, appearing as Lilienthal, conducted flying trials for a film. In 1985 the Otto Lilienthal Museum commissioned Stephan Nitsch from Magdeburg to reconstruct those flying machines of Lilienthal which were no longer in existence. Studying all the drawings, photographs and other sources, it has since been possible to make reconstructions of the flying machines which are identical to the originals.
Instructions on fixing the so-called "buffer frame" in a letter from Lilienthal to the Munich aeronautical engineer Alois Wolfmüller, 1894
Aerodynamic trial of a glider replica on the test vehicle of the German Hang-glider Association
Flying a glider replica as a kite Flying trial of a replica, 1989
"I am able now to fly two to three hundred metres
from elevated points, a most interesting and healthy pursuit. If only
I could call such a flying sport into being ..." - Otto Lilienthal
After the realization of motor-powered aeroplanes, sailplanes came into being in the 1920s. But it was not until 1948, after the development of "flexwings" by the NASA engineer Francis Rogallo, that the technology was developed, in the form of the hang glider, to which Lilienthal's dream of "personal aerobatics" probably comes closest.
"As a missionary he was admirable. He presented the process of human flight so seriously, so attractively, so convincingly, that it was difficult for anybody to resist the temptation to try it out for themselves ... whatever his limitations he was without doubt the greatest of the pioneers and the world is deeply indebted to him." - Wilbur Wright 1912
On 17 December 1903 the brothers Wilbur (1867-1912) and Orville Wright (1871-1948) made the first powered flight (36 metres in 12 seconds). The Wrights continued with results and methods of Lilienthal. They perfected the step from the "winged man", a concept from Leonardo da Vinci to Lilienthal, to the inherently stable aeroplane. They also developed better solutions for steering and drive.
summary of exhibition displays
The Lilienthal Brothers - life and accomplishment
Dream of Flight
The Lilienthal Brothers
Otto Lilienthal 1848, May, 23. - 1896, August, 10.
Gustav Lilienthal 1849, October, 9. - 1933, February, 1.
America - the new world - was supposed to be the way out of the financial difficulties of the draper Karl Friedrich Gustav Lilienthal and his wife Caroline from Anklam. But the sudden death of Gustav Lilienthal prevents their plan to emigrate. At this time four out of eight children are still alive. Otto is 12, Gustav 11 and Marie 4 years old. Anna, only three months old, dies half a year later.
The mother's purpose in life becomes making an education possible for the children in spite of these facts. After the father's death, Wilhelm, an uncle from Greifswald and later merchant Mehlhorn, a friend of the family, take over the guardianship. The papers about the guardianship are preserved. in 1894 they state about both brothers: "physically and mentally healthy, moral behaviour good, Otto: destined to be a mechanical engineer".
Lilienthal went down in history as the "first flying man". But this reveals only a part of his life:
Otto Lilienthal was a successful manufacturer of small save steam engines and steam boilers
As a creative engineer he held numerous mechanical engineering patents
He was a progressive, social thinking entrepreneur
He ran a theatre in which he also worked as an author and actor
He dealt with the flying of humans in lectures, in the society for Promoting Aviation and in experiments
His centre of life was the "engineering Works Otto Lilienthal" in the Köpenicker Street in Berlin. The "Normalsegelapparat" (Standard Glider) that was mass-produced there from 1893 onwards was an alien "special model" for the company. With this apparatus the factory became the first aeroplane factory in history. It is sad that this place of world history in the centre of Berlin is today totally forgotten in Germany.
Two vices, a lathe and the patented idea of new steam boiler - is the start-up capital of the "Engineering Works Otto Lilienthal" in Berlin, which developed to be a successful and well-known company.
Together with Lilienthal's small steam engines the save boiler enables small companies to use machine power, too.
But Lilienthal does not only write steam engine history: As the first entrepreneur in Berlin he abolishes piecework wage and introduces profit sharing for his workers.
The famous "Anchor stone building blocks" - model for all construction toys up to this day - is one of numerous inventions of toys and boxes of bricks of Gustav Lilienthal. in these, tree of his most important interests and fields of activity are united: pedagogics, architecture, arts and crafts. Otto Lilienthal contributed to the invention.
First the brothers try to put their invention on the market themselves but then they give it to the manufacturer Richter in Rudolstadt/Thuringia for a small fee. Richter makes a success story worth millions out of it. Later the brothers try to produce bricks again themselves, which leads to a costly lawsuit against Richter.
Although the box of bricks was a big economical failure, the proceeds of 6000 Marks formed the basis for their future lives: Gustav paid the passage to Australia and Otto founded his factory.
Lilienthal calls his plane a "cultural element". His vision of everlasting peace as a result of his invention will always be connected with his name, although he was mistaken.
Other projects of the brothers are connected with social and cultural visions, too:
In Lobetal near Berlin, the first shelters for the homeless that were fitting for human beings were built with Gustav Lilienthal's invention of prefabricated parts for house building. The association "Obstbaukolonie Eden" and "Freie Scholle" used his patent to built their reformed housing estates. His numerous toys contributed to a form of reformed pedagogic, his "school for female handiwork" to a new understanding of art.
Otto Lilienthal becomes co-owner of a Berlin theatre, that he restructures to a theatre for "the labour force of the surrounding boroughs". He writes a socio-critical play, the "Modern Robber Baron". He introduces profit sharing for the work force in his company. The influential social moral philosopher Moritz von Egidy writes in an obituary: " The engineer Otto Lilienthal took part in all serious cultural efforts. He was a thinker who knew what he was doing and who put thoughts into practise; at the same time of gentle mind."
time of change
The Lilienthal brother's philosophy of life was "political" in a today nearly forgotten way. They believed that the new opportunities: machine power, long-distance traffic, industry and education would lead to a fundamental reshaping of the life of every individual and of society. With this idea they were not alone:
On the threshold of the 20 th century, a complex movement to social and cultural reforms developed alongside the big political camps. It covered a variety of areas and walks of life. Although the reformers never had a united organisation, many understood themselves as representatives of a "third way". The ideas of the "reform movement" can today of course be found in political programs like ecology, liberalism, equality and welfare state. Other ideas are probably wrongly forgotten, like free money, free land, shrinkage interest and natural economic system.
Dream of flight
Stone Age Pilots
Today we call Lilienthal the first flying man in the history of mankind. But was he really the first? What are the origins of tales about Daedalus, Ikarus and Wieland the smith? Were the ground drawings in Peru really made by alien pilots? The description of flying humans is as old as mankind. How old is the flying human really?
The geoglyphs of Nasca:
In 1939 huge ground drawings (lines, planes, drawings of geometry and animals) were discovered during a flight over the Peruvian plateau between the Pacific and the Andes. The drawings are hundreds of years old and originate from the Nasca-civilization that is older than the Inkas. The drawings are so big that you can only see them from the air. Their purpose is unknown. There are many different hypothesis concerning their interpretation. The most plausible to us is the one by A. Steinmann from Würzburg. He thinks that it is a prehistoric runway for manned kites and hang gliders in captive or free flight (see: www.lilienthal-museum.de www.lilienthal-museum.de ). The drawings of geometry and animals could be heraldic markings for the different landing strips.
The first aircraft used by mankind was not the balloon. Kites have a history of more than 2000 years in China and was used for manned takeoffs as well. At the beginning of the 20 th century the kite is also a common aircraft used by the military and meteorology in Europe.
Forty years ago the kite became a modern aircraft. The flexible kite designed by the NASA-engineer Francis Melvin Rogallo lost its ties and became the free flying Rogallo-wing. Later for the second time in history an airplane, the ultra light, developed from this hangglider.
In contrast to the airplane the concept of the hangglider is simple and thinkable at an early point of history. Are gliding flights hidden behind traditional flight myths and legends?
To rise, to lift up out of the worldly vale of tears, to the light, to the sky, the seat of the gods - that is an old wish of mankind. Because this will not come true, he gives the ability to his gods and demons: witches ride on brooms through the air, winged creatures live in myths and legends, a proud bird of prey is enthroned in Anklam's coat of arms.
But pioneering spirit tried to decipher bird flight that seemed to be so perfectly natural without the help of magic. Amazing ideas, fantastical projects and breakneck tests are lost in the dark history of human aviation.
In 1829 the Frenchman M. Daguerre (1787-1851) and J.N. Niepce (1765-1833) had started to "get pictures of the views that nature presents to us without the help of a painter" - to take photographs. The "Daguerreotypie" makes "silhouettes" of nature possible, not "snapshots" like flying birds or galloping horses. The Leipziger Stadtanzeiger writes in 1839: "The attempt to get a picture of fleeting reflections is not only impossible, ... but even the wish ... is blasphemy."
Since 1882 Ottomar Anschütz from Lissa/Posen, today Berlin, had been engaged with the attempt to outwit the "moment" with the help of photography. His focal-plane shutter was the key to the production of "moment photography". A series of flying storks belongs to the first moment photos in 1884. In 1890 he succeeded in putting studies of moving humans and animals together in such a way that moving pictures were created. His so called "fast viewer" that was based on this method was a crowd puller at the world exhibition in Chicago in 1893.
The legend of Ikarus (around 750 BC) is the classic idea of the realisation of flying man. Wieland the smith from the Nordic Nibelungen-Saga uses the same method to fly - with artificial wings attached to his arms. Remarkable technical details - like the necessity of taking off against the wind - are included even in these legends.
human flight"From the crest of the hill the great bird will take his first flight, filling the universe with wonder, all chronicles with his fame. And eternal glory be to the place he was born."
- Leonardo da Vinci 1497
With thousands of gliding flights by Otto Lilienthal with different gliders between 1891 and 1896, the era of the airplane as a means of human flight began.
Lilienthal's success and international recognition goes back mainly to his successful gliding flights from 1891 onwards. His experimental groundwork and tests starting from 1873 are fundamental for aviation up to now. In his book "Bird Flight As The Basis Of Aviation" published in 1889, he presented the physical laws of the wing that are still valid today.
"That day in 1891 when Lilienthal paced the first 15 metres of air, I take as the moment when mankind learned to fly." This statement by the French flight pioneer Ferdinand Ferber (1862-1909) becomes part of the history of aviation. "That day" though is not exactly known.
After 1891 Lilienthals airplanes and airfields developed quickly. From the stiff constructions the collapsible batwing was developed, basis for all following airplane constructions.
In the surroundings of his flat he searches for a suitable ground that could serve him as an airfield. In 1893 a wooden takeoff plateau, his "flight station", was built in Lichterfelde. In 1894 he put up his 15 metres high "flight hill" close by.
The Rhinower hills, a range of hills 100 kilometres northwest of Berlin, become his "power airport" for flights up to a distance of 250 metres.
In 1896 Lilienthal experiments with flapping wings, mechanical flight control systems and biplanes. Gliding flights with the "Normalsegelapparat" (normal glider) are routine.
On the 9th of August during such a flight in the Rhinower hills he did not manage to balance a gust of wind. The front of Lilienthal's apparatus was lifted up and the glider nearly stood still in the air. In this position it is not possible to control the flight anymore. The apparatus tipped over one wing and crashed down. Lilienthal died from his injuries of the spine on the following day.
"Columbus made a new continent accessible, the Montgolfiers the sky." With these words the first balloon trips were celebrated in 1783. Characteristic for the following century were the unsuccessful attempts to make the balloon manoeuvrable. Aviation was not marked by the competition "lighter than air" versus "heavier than air" - airship against aeroplane- until the early 20th century. Only the airship catastrophes in the 1930s helped the airplane to victory.
The first idea of human flight was the imitation of birds - a flying object "heavier than air". With the successful balloon rides of the 18th century the concept "lighter than air" - aerostatics - became the centre of research. "We may say that the balloon was not really helpful for free flight, if we want to avoid to say that the air balloon was an obstacle to the development of aircraft engineering. Because the balloon divided the interests and lead the research that was supposed to serve free flight into the wrong direction" Lilienthal writes.
With his experiments he laid the basis for aircraft engineering in physics. His successful flights were imitated in different countries and helped to get the concept "airplane" to being accepted.