By: Rénald Fortier
Ingenium – Canada's Museums of Science and Innovation
“I preferred to be a cutting edge engineer” The most important rocketry pioneer you have never heard of, the French engineer and inventor Louis Damblanc, part 2
Static test of a rocket engine by Louis Damblanc, Saint-Cyr-l’École, France, March 1932. Pierre Rousseau, “Où en est la technique de la fusée? » La Nature, 15 July 1936, 59.
Hello, my reading friend. How are you? […] Good, good.
Now that the name of French space exploration pioneer Louis Damblanc is no longer unknown to you, the time has come to see why the name of that engineer is worth knowing.
In March 1932, Damblanc carried out a series of solid propellant rocket tests in Saint-Cyr-l’École, France, a suburb of Paris, in collaboration with the Institut aérotechnique, a research establishment located in that town. He wished to obtain precise data on the performance of the engines of said rockets, with the ultimate goal of developing (military? postal? other?) rockets which could reach high altitudes and / or travel long distances.
Those experiments were carried out with the support of the Office national des recherches scientifiques et industrielles et des inventions, an organisation created under another name in 1919 under the supervision of the Ministère de l’Instruction publique et des Beaux-Arts.
Damblanc carried out his experiments with anti-hail rockets used to prevent the formation of large hailstones during storms and line throwing rockets used to launch a cable to enable the rescue of crews whose ships were wrecked near a coast.
Louis Damblanc’s test bench, Saint-Cyr-l’École, France. Two recorders were located on the base of said test bench. Louis Damblanc, “Les fusées autopropulsives à explosifs.” Recherches et Inventions, April 1935, 112.
By the way, Damblanc designed and manufactured his own test bench, a device of almost revolutionary type for the time. That test bench and the tools surrounding it were in fact capable of (simultaneously?) recording numerous variables, automatically and permanently. Gone were the feverish moments during which the designer of a rocket had to write everything down by hand, for fear of losing data.
And yes, you are absolutely right to believe so, my reading friend, Damblanc took care to film in slow motion virtually all the tests of the rocket engines. He went so far as to record the sound produced during said tests.
In short, it was a real research program that the French engineer set up.
And you have a question, me rocketphile reading friend… Was Damblanc considering several, or even many, civil or military applications for future rockets? Yes, of course, from the transport of supplies to postal flights. Indeed, Damblanc considered equipping them with helicopter parachutes, in other words parachutes whose descent was slowed by a rotating wing.
Aware of the usefulness, if not the necessity, of minimizing the size and cost of future rockets, Damblanc also considered the possibility of launching them from more or less imposing cannons.
That concept was deeply similar to that of a Canadian-American military high altitude research project developed independently, the High Altitude Research Project (HARP), in existence between 1961 and 1967.
Indeed, one of HARP’s two gigantic guns fired the first of a long series of Martlet finned projectiles in February 1963. In November 1966, one of those reached an altitude of 179 or so kilometres (111 or so miles), something unheard of. No Martlet was ultimately placed in orbit however, and this even though that was the goal of the project.
This being said (typed?), a Martlet which was never launched is part of the collection of the incomparable Canada Aviation and Space Museum, in Ottawa, Ontario, but back to Damblanc.
Would you believe that the management of the l’École militaire spéciale de Saint-Cyr, in… Saint-Cyr-l’École, apparently required Damblanc to buy insurance? Those officers feared that school buildings could be damaged or even destroyed during his experiments.
Although various personalities from the world of science attended Damblanc’s tests, the staff of the Section technique de l’aéronautique of the Ministère de la Guerre apparently declined Damblanc’s offer to see what was going on.
From 1937 onward, Damblanc completed numerous rockets with more than one stage – a 20th Century world first. A good number of them reached for the sky and functioned perfectly, as shown in the following photograph.
The only photograph known by yours truly which shows one of Louis Damblanc’s 2-stage rockets in flight, Saint-Cyr-l’École, France, 1935. The photographer captured the moment following separation of the second stage of the rocket and the start-up of its engine. A. Ananoff, “Reparlons des fusées gigognes. » L’Aérophile, April 1, 1947, 102.
Those experiments might, I repeat might, have been carried out under the aegis of the l’Office national des recherches scientifiques et industrielles et des inventions.
As you might imagine, Damblanc developed a device to ensure the separation of the stages of his rockets. That device was the first of its kind in the world.
Some of Damblanc’s solid propellant rocket engines were among the best performing of their time.
Damblanc obtained the solid propellant in question, a high quality compressed black powder, thanks to the tender mercies of an institution which really knew its powders, the École centrale de pyrotechnie of the Ministère de la Guerre, in Bourges, France, in the central region of Berry.
Would you believe that one of the rocket engines tested by Damblanc was the most powerful tested so far in France? The jet of burning gases it emitted was a good ten metres (nearly 35 feet) high. Wah!
It was also within the framework of those experiments that Damblanc supervised the launch of a 3-stage rocket, the most powerful rocket launched in France before 1950, and the launch of the first Véronique rocket, designed by engineers from the Laboratoire de recherches balistiques et aérodynamiques.
An interesting detail, if only for yours truly, a few weeks, or even just a few days, separated the launches of the first two 3-stage rockets tested on our big blue marble, in 1937. If Damblanc launched the first, the fact was that a Scottish team, the Paisley Rocketeers’ Society, launched a rocket of that type at the end of December of that same year.
Ultimately, during the second half of the 1930s, apparently between 1937 and 1939, Damblanc supervised approximately 360 rocket launches, including at least 120 at the Champ de tir du Polygone in Bourges. He designed no less than 150 of those rockets himself.
Damblanc used a tilting device to perform these launches. And no, said device did not appear to be tilted during launches. Damblanc realised very well that a rocket which was not launched straight up might not be found.
Signal rockets designed by Damblanc might, I repeat might, have been used in the Sahara Desert in 1938, and this by an unidentified French civilian or military team.
And yes, the French patent for multi stage rockets granted to Damblanc in June 1936 was the first of its kind in the world, a priority recognised in December 1960 by the Internationaal Octrooi Instituut, a European organisation based in the Netherlands.
A cautious inventor, Damblanc took the precaution of obtaining similar patents in the United States, the United Kingdom, Japan and Germany.
By launching his first rocket with more than one stage, Damblanc was bringing to life a concept imagined in 1929 by the Russian / Soviet cosmonautics pioneer Konstantin Eduardovich Tsiolkovsky. That concept was the multi-stage rocket or, as Tsiolkóvskiy said (typed?), the kosmicheskiy raketnyye poyezd, in English space rocket train, an enormous spaceship equipped with 20 single-stage rockets that Tsiolkóvskiy imagined going to the Moon in 2017, but back to Damblanc and…
Goddard obtained an American patent for a multi stage rocket in July 1914, you say, my reading friend who likes to dot the i’s? And a French physician, André Bing, had done the same in 1911? I stand corrected.
Mind you, Bing was also not the first Homo sapiens to come up with the idea of the multi stage rocket either. Nay. In fact, no one really knows who had that idea before anyone else.
What we know is that the germanophone pyrotechnician and pioneer of rocketry Conrad / Konrad Haas published a text which mentioned the concept of the multi stage rocket even before 1560. Better yet, before the year 1600, the germanophone pyrotechnician / military engineer and rocketry pioneer Johann / Johannes Schmidlap / Schmidlapp designed, manufactured and launched multi stage rockets containing fireworks.
Please note that yours truly used the term germanophone because Germany did not exist in the 16th century. Its territory then roughly corresponded to the hodgepodge of feudal territories known as the Holy Roman Empire, an entity which, to quote the French writer / poet / playwright / philosopher / encyclopedist François-Marie Arouet, better known as Voltaire, was in no way holy, nor Roman, nor an empire, but I digress.
And yes, Arouet was indeed mentioned in June and October 2023 issues of our explosive blog / bulletin / thingee.
In June 1935, Damblanc was the recipient of the Prix d’astronautique, or Prix REP-Hirsch, awarded more or less annually since 1929 by the Comité d’astronautique of the Société astronomique de France, a prestigious organisation mentioned in June and November 2019 of our equally prestigious blog / bulletin / thingee. Said prize and the sum of money which seemed to accompany it rewarded perhaps more the publication of a text on the tests of rocket engines on a test bench than the tests themselves.
The numerous tests carried out by Damblanc constituted one of the first, if not the first, in-depth study of what happened inside solid propellant rocket engines.
By the way, André Jean Henri Louis Hirsch was a banker from Paris. The acronym REP, for its part, hid the pioneer of French aeronautics and astronautics Robert Albert Charles Esnault-Pelterie.
Before I forget, Hirsch had financially supported Aleksandr Mikhranovich Ananoff, the young spacenut mentioned in the first part of this article, when the latter decided to present conferences intended for the general public, in 1929.
A left-wing reformist and not a Marxist, Damblanc served as mayor of the town of Fleurance, France, in the southern region of Aquitaine, from December 1928 to February 1941.
His lack of enthusiasm for the collaborationist and authoritarian puppet government set up in Vichy, in the south of France, after the fall of that country in June 1940, led to his dismissal. He was replaced by a special delegation.
We are entitled to wonder if Damblanc knew that, around 1942-43, an American organisation, the Alien Property Division of the United States Department of Justice or the Office of Alien Property Custodian of the Office of Emergency Management, I cannot say which of the two, seized his American patents, including that on multi stage rockets, granted in April 1938. A seizure which could not be more legal, because it was authorised by a legislative measure, the Trading with the Enemy Act of 1917, which authorised the seizure of patents from enemy countries.
Yours truly wonders if that seizure took place shortly after the severance of diplomatic relations between the American government and the Vichy regime in November 1942, the date of the takeover by National Socialist Germany of the southern portion of France, controlled until then by that puppet, collaborationist and authoritarian government. A takeover which followed the Anglo-American assault launched against two French possessions in North Africa, namely Algeria and the French protectorate in Morocco, in November 1942.
While it was true that Damblanc undertook certain theoretical work on rockets around 1944-45, the fact was that he reinvented himself from the second half of the 1940s onward.
He presented in fact examples of his episcope / opaque projector, sometimes known as the lecteur Damblanc, and this from 1950. That device made it possible to project, apparently in broad daylight, images enlarged around 10 times of opaque documents (maps, drawings, etc.) placed on a work table.
Yours truly remembers receiving an episcope as a gift, in the mid 1960s, a Rainbow Crafts Magnajector to be more precise, the De Luxe version of that magnifier projector actually, but I digress.
Before long, Damblanc marketed a device which was both an episcope and a device capable of enlarging transparent documents (slides or negatives for example), in other words an overhead projector or epidiascope. At least one model of that hybrid device, the imagiscope, could enlarge a document about 1 600 times, or much more. Wah!
Mind you, the imagiscope could also be used to examine mechanical parts under high magnifications (up to 30 times their real size?).
Oh, before I forget, Damblanc developed a microfilm reader no later than 1952.
You will no doubt be delighted to learn that the imagiscope enjoyed some commercial success. Its versatility earned it orders from various French ministries, Postes, Télégraphes et Téléphones, as well as Éducation nationale and Défense for example. Indeed, any teaching community which purchased one of those devices could be granted a small subsidy by the Musée pédagogique of Paris, a national museum whose function was to improve teacher training.
It went without saying that the versatility of the imagiscope also earned it orders from various organisations, from banks to dental schools, as well as daily newspapers and textile factories.
Damblanc also designed a prototype of an automatic film viewer with paper support operated by coins. The French publishing house Hachette Société Anonyme actually planned to place such devices on thoroughfares in order to allow passers-by to see a subject (news, advertisement, etc.) chosen by the person who had rented said device. The French giant soon changed its mind, however.
As active as he was in the field of image enlargement, Damblanc held a part-time engineering position in a French aeronautical state firm, the Société nationale d’études et de construction de moteurs d’aviation, from 1956 onward.
In July 1965, the French Ministère des Finances et des Affaires économiques awarded Damblanc a compensation for any use of two of his patents by the American government during the Second World War. That compensation might, I repeat might, have required long and difficult negotiations. The organisation responsible for the French space program, the Centre national d’études spatiales, might have supported Damblanc in his efforts.
A little before or after that date, the American government provided awarded a symbolic compensation to the French engineer, thus recognising the use of his patents during the Second World War.
At the end of September 1967, in Belgrade / Beograd, Yugoslavia, now in Serbia, during the XVIII International Astronautical Congress, organised as usual by the International Astronautical Federation of Paris, the international astronautical community recognised Damblanc’s achievements during the 1930s and paid homage to him.
Damblanc was seemingly not present at that event.
This being said (typed?), a paper he wrote on his work in the 1930s was seemingly presented or tabled as part of the first international symposium on the history of astronautics, a symposium organised by an organisation based in Paris, the International Academy of Astronautics, as part of the XVIII International Astronautical Congress.
Damblanc left this world in December 1969, at the age of 80.
Fairly forgotten at that time, Damblanc is forgotten even more so in the 21st century, which is a shame, you will agree with me.
Rénald Fortier
More Stories by
![A block of photographs showing some of the people involved in the bombing of beluga whales in the estuary and gulf of the St. Lawrence River. Anon., “La chasse aux marsouins [sic]. » Le Devoir, 15 August 1929, 6.](/sites/default/files/styles/thumbnail_7/public/2024-09/Le%20Devoir%2015%20aout%201929%20page%206.jpg?h=584f1d27&itok=TppdLItg)
![Peter Müller at the controls [sic] of the Pedroplan, Berlin, Germany, March 1931. Anon., “Cologne contre Marseille – Le mystère du ‘Pédroplan.’ [sic]” Les Ailes, 2 April 1931, 14.](/sites/default/files/styles/thumbnail_7/public/2021-04/Les%20Ailes%202%20avril%201931%20version%20big.jpg?h=eafd0ed4&itok=WnBZ5gMf)
![One of the first de Havilland Canada Chipmunk imported to the United Kingdom. Anon., “De Havilland [Canada] DHC-1 ‘Chipmunk.’” Aviation Magazine, 1 January 1951, cover.](/sites/default/files/styles/thumbnail_7/public/2021-01/Aviation%20magazine%201er%20janvier%201951%20version%202.jpg?h=2f876e0f&itok=DM4JHe5C)
