Movements of Air Etienne-Jules Marey (1830-1904) Photographer of Fluids

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Etienne-Jules MareyTriangular prism presenting one of its bases to the air stream, fourth and lastversion of the smoke machine equipped with 57 channels© Cinémathèque française
Etienne-Jules Marey (1830-1904) - physiologist, doctor, biomechanics engineer and inventor in 1882 of chronophotography, a technique anticipating cinematography. He devoted three years at the end of his life, from 1899 to 1909, to photographing movements of air.

The beauty and enigmatic character of his shots of smoke are striking to today's visitors, but they also raise numerous questions. Why were these pictures produced  ? What was the purpose of the research and with what techniques were they conducted  ? Why did he turn to instant photography at a time (1899-1902) when chronophotography and cinematography were already commonly used  ? To understand this, one has to go back to the origins of the technique that dominated the physiologist's life and work: the graphic method.

This consisted in transcribing on paper or on a sensitive surface the forces exerted on a body in motion, whether it be living or inanimate.

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Etienne-Jules MareyTriangular prism presenting one of its angles to the air stream, fourth and last version of the smoke machine equipped with 57 channels© Cinémathèque française
As Marey stated in La méthode graphique dans les sciences expérimentales (1878), this method allows observing and measuring the "relation of space to time that is the essence of motion". Using transcribing devices, the traces of movements or phenomena that human senses are most often unable to perceive were captured for the first time.

In the 1890's, after studying fish locomotion using chronophotography, Marey sought to understand how a liquid reacts to the passing of any object. He laid small silver-coloured balls made of wax and resins in water agitated by means of a propeller. The sunlight was reflected in these tiny bright bodies in suspension, and the effects caused by an obstacle set on the trajectory of the current were thus recorded at a rate of 42 images per second. It was this device that gave him the idea of making a similar experiment with wisps of air produced by a wind tunnel.

 

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Etienne-Jules MareyTilted plane, 60-degree angle, fourth and last version of the smoke machine equipped with 57 channels© Cinémathèque française
At the end of the 19th century, Marey was not the only scientist who wanted to observe movements of air.

As early as 1893, a German, Ludwig Mach, designed a smoke machine lit by an arc lamp. Marey's wind tunnel was to operate on the same principle. In England, Professor Henry Selbe Hele-Shaw studied hydrodynamics photographing streams of coloured glycerine. But Marey was not yet aware of the currents when, in 1899-1900, he started studying aerodynamics using the smoke produced by a machine. He was merely pursuing a line of thought constantly present in his work: how could one observe the invisible  ?

When he first started researching this field, in the 1860's, Marey thought that the future of aerial locomotion was likely to be found in a machine able to flap its wings. He later abandoned this hypothesis to become a fervent supporter of aeroplanes.

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Etienne-Jules MareyTilted plane, 30-degree angle, fourth and last version of the smoke machine equipped with 57 channels© Cinémathèque française
In The Flight of Birds (1890), Marey explained that "From the point of view of the resistance experienced, whether the solid body be in motion in calm air or whether it be immobile in an air animated with movement is indifferent." He thus presented the first principle underlying his later smoke machines: air propelled against an unmoving form. He was then tackling a subject that had almost never been studied before: the problem, crucial for aviation, of the air flow around a surface.

Marey imagined the following process in order to allow aviators to make progress: " Produce a steady stream of air within a closed device with transparent walls; introduce parallel and equidistant wisps of smoke; on the trajectory of these wisps of smoke, place diversely shaped surfaces, at the contact of which they change their course; light brightly and take an instant photograph of their appearance. Such was the programme."

Marey built his first wind tunnel in 1899. The first photographs he presented to the Academy in 1900 allowed, he explained, a better understanding of the action of the bird's wings on the air: "It was important to make experiments showing the direction taken by the wisps of air when encountering the surface of a more or less inclined wing presenting a variable curvature."

 

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Etienne-Jules MareyFourth and last version of the smoke machine equipped with 57 channels© Cinémathèque française
Marey was to build four different versions of his wind tunnel, transforming progressively the first version, adapting old elements to new ones. He started with a 13-tube machine, the results of were deemed unsatisfactory. He went on with an 11-tube machine, followed by a third version, with 21 tubes. Yet as far as we know not a single shot resulting from these first three smoke machines was published by Marey, who no doubt was not yet completely satisfied with his process. In his very first communication to the Academie des Sciences about his wind tunnel, on July 16, 1900, Marey announced forthcoming new experiments "with improved devices."

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Etienne-Jules MareyNormal 5-centimeter plane, fourth and last version of the smoke machine equipped with 57 channels© Cinémathèque française
In 1901 Marey was granted subsidies by the Washington Smithsonian Institution, thanks to the American pioneer of aeronautics Samuel Pierpont Langley. This allowed him to fund a 57-smoke-stream machine in 1901. A 20-centimeter ruler and an "electric trembler" that shook the small tubes ten times per second were added. One could thus compute the speed of the air by observing the course of the slight oscillations that formed regularly along the wisps of smoke.

The pictures he obtained thus represent the behaviour of the air when encountering a plane inclined according to various angles and, from the very first photographs, Marey noticed results similar to those he previously obtained while studying the movements of water.

This latter version seems to have fully satisfied Marey as, on June 3, 1901, he presented four pictures to the Academy and gave the description of the new wind tunnel.

Some of his shots certainly saved the lives of many aviators, as for the first time one was able to see the invisible - the way air reacted to certain forms.<

 

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Etienne-Jules MareyTriplanes, 30-degree angle, fourth and last version of the smoke machine equipped with 57 channels© Cinémathèque française
On the whole, Marey, after he published his aerodynamic pictures, left but few theoretical comments. He may be said to have been little-interested in the scientific results derived from his shots.

The penultimate article Marey devoted to the machine, published on September 7, 1901 in La Nature ended with the following lines that show the physiologist had already turned to another subject: "One may easily conceive the multiplicity of problems that may be solved by this method. We have described it in detail, so that it may be used by all those who are concerned with aviation, propelling in fluids, ventilation, all things related to movements of air."

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Etienne-Jules MareyThree associated concave surfaces, 30-degree angle, fourth and last version of the smoke machine equipped with 57 channels© Cinémathèque française
Such an attitude on Marey's part was not surprising. He was a polymath and a prolific scientist who tackled any subject that bore a relationship with his obsession: motion. The mission he undertook was above all to record graphically the trace of movements, to make them visible. He left to others, more competent in their fields, the task of analysing the pictures thus obtained. Sometimes, when he mastered the subject, he perfectly accomplished this difficult work.

But Marey, besides his deficiencies in mathematics, always had a certain inability to adopt the approach of a physicist. Here one has the sensation he was mainly fascinated by the sight of his machine, by the hypnotic beauty of his shots. In any case, if Marey soon abandoned his wind tunnel, he nonetheless initiated in France a fundamental technique. Wind tunnels on the type of Marey's are still in use in research and industrial laboratories. Smoke wind tunnels continue to be built with more modern and costly means, but which produce magnificent instant pictures very similar to those made by Marey in the early 20th century.

 

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Etienne-Jules MareyTilted plane, 65-degree angle, third version of the smoke machine equipped with 21 channels© Cinémathèque française
There is nothing left today of Marey's various smoke machines. They were destroyed when the Station Physiologique and the Institut Marey were demolished to allow the extension of the Roland Garros stadium in 1979.

Thanks to an exceptional subsidy of the Centre National de la Cinématographie, the Cinémathèque Française in 1999 was able to reconstruct one of Marey's machines. On the occasion of this exhibition, organised with the Cinémathèque Française, the Musée d'Orsay has built four more.

It may seem strange that Marey, after initiating chronophotography, should have come back to instant photography towards the end of his life. But once more he was merely anticipating a certain aesthetic and technical trend of modern cinema, either fictional or scientific. Marey liked to use a high rate of frames per second. As early as the beginning of the 1890's he reached a rate of 100 images per second in his films.

Pierre NoguèsStandard 20 cm shot, fourth and final version of the smoke machine, equipped with 57 ducts© Cinémathèque française
Paradoxically, multiplying the frequency of pictures by a million or a billion, one eventually somehow ends up producing a kind of super-instant photograph, precisely what Marey recommended at the end of his life to capture the flux of movements of air.

In addition, the pictures made from 1899 onwards strongly evoke the iconography of the graphic method: white lines on a black background. On several occasions, Marey referred to his smoke photographs not as "instant pictures" but as "chronophotographs", while this term should normally apply only to sequenced studies of movement. This was no doubt because Marey's instant pictures are comprised as much of ‘chrono', ‘photo' and ‘graph': ‘chrono', thanks to the undulation of channels of smoke; ‘photo' with the flashlight and the photographic camera; ‘graph', finally, because the luminous sills left by the smoke channels on the sensitive plate may be read and analysed like graphs.

Marey thus operated a sort of return to his roots and brilliantly wound up fifty years of research on graphic representation and its enigmatic black and white world.

 

 

dam width="144" float="right">100385The technique of wind tunnels was improved in the early 20th century by engineers and aeroplane and automobile constructors. The most famous example, a few years posterior to Marey's, is the aerodynamics laboratory of Gustave Eiffel (1832-1923) in Auteuil. As for studies on the resistance of air and the law of gravity, Eiffel followed the same itinerary as Marey: he started with the graphic method and ended with the wind tunnel. But unlike Marey, Eiffel was to establish, based on the same principles, all kinds of laws that would be taught in engineering schools.

Organised on the occasion of the centenary of Etienne-Jules Marey's death, this exhibition presents a previously little-known period of Marey's work. But as in his famous chronophotographic films, smoke pictures and reconstructed machines offer a sight in which art and technique are successfully intertwined. The resulting images are exceptionally beautiful and endlessly captivating. On the occasion of the first Marey exhibition, organised at the Cinémathèque Française in 1963, Henri Langlois described the physiologist's work in these terms: "nothing is more secret, nothing is more lyrical, nothing is more explosive, nothing is more modern than the silence of his blacks and the lightness of his whites."

This text was written after Laurent Mannoni's article in the catalogue Mouvements de l'air, Etienne-Jules Marey, photographe des fluides, joint edition Gallimard / Réunion des musées nationaux, Collection "Art et artistes", 2004.