Louis Le Chatelier
Louis Le Chatelier
Portrait of Louis Le Chatelier, engineer
Biography
Antoine de Lavoisier is one of the 72 scientists whose name is inscribed on the first floor of the Eiffel Tower. He is 5th, on the east facing side.
Louis Le Chatelier, an engineer, was born in Paris on February 20, 1815. He died in the same city on November 10, 1873, kidnapped prematurely at the age of 59, in intellectual strength and the brilliance of fame. A multifaceted, broad-minded and encyclopedic artist, the art of mining and metallurgy, the exploitation of the railways, and agronomy, owe him first-class work. It was a creative intelligence, with the very practical sense of immediate popularization. He can also be considered as one of the founders of railway lines in France.
Louis Le Chatelier is perhaps one of the most modest among these celebrities, but he is not one of the least deserving and one of those whose work is the least fruitful. It was mainly in the last years of his life that we were able to observe him very closely, at the time when he had just acquired a property in a newly desiccated part of the Landes department, west of Bordeaux. . He had conceived the project of completing the reorganization by a new method, and by means of special fertilizers, the nature of which he had studied, and the composition of which he had made according to the elements of the land, of which he had made many analyzes. On these special questions of agricultural chemistry, he had, in my presence, frequent conferences with my father, who was very competent in the subject.
Louis Le Chatelier had done brilliant studies in Paris, at the Roilin College, the year of his entry into the Ecole Polytechnique, with an unusual success: the first prize for special mathematics and the second prize for physics at the Concours general. He was admitted in 1834 into this glorious establishment, the nursery of most of the great scientists of the nineteenth century. In 1830 he came out in the first numbers to go to the Ecole des Mines. He completed his studies there in just two years, and after that he completed a single seven-month training trip to northern France, Belgium, and then Germany.
At that time, the mining and metallurgy industry took off. Louis Le Chatelier applied his remarkable aptitudes, after having observed the state of all the technical questions. Thus he lives in the department of the Pas-de-Calais research polls that were done to find the extension of the coal basin of the North Department, research that was then unsuccessful, but which were to be taken a few years more late with a resounding success. In Belgium, he visited the many new or newly created iron mines. In Germany, he studied the first mechanical ladders and the first uses of wire rope used for extraction, replacing cables or chains. He also studied the use of hot air, invented a few years earlier in Scotland for blast furnaces, and which was beginning to play an important role in metallurgy. He thus devoted himself to the new methods by which Plattner, in Scotland, showed that the torch, under certain conditions, could become a very valuable instrument for the quantitative and qualitative analyzes of metallurgical chemistry.
The result of this trip, fruitful in long studies, was the successive composition of four important Memoirs, which obtained the honors of the insertion to the Annals of Mines. This finished work, Louis Le Chatelier was sent in residence to Angers with the title of aspirant, and was appointed ordinary engineer second class, June 1, 1841. From the industrial point of view, the country was only of importance secondary. For an inquiring mind, this limited field of action should not remain sterile. Louis Le Chatelier took advantage of his situation to undertake the new and complete study of the coal beds of the Vendée basins, as well as the iron ores around Segré, exploited by the old and then abandoned. He pointed them out to the attention of the forge masters, and it is from that time that they took on a serious importance. In these functions, he also studied the action of corrosive waters used in mines and quarries in the supply of steam boilers. His memoir was appreciated in high places and considered important enough by the superior administration to be inserted in the Annals of the Mines, then pulled apart and sent to the prefects with an official circular dated October 12, 1841.
At this moment, we are touching on a solemn era for France and for Louis Le Chatelier's career. It was at this moment that the great railway industry, after long hesitations and unfortunate predictions, remained famous, because they were emitted by illustrious orators, in our political chambers, was finally to take on a development in France. final. At the end of 1842, we still had only 600 kilometers of railway lines, in isolated sections, in the Loire, the North, Alsace, Gard, Herault. From Paris itself, one could only go by rail to Saint-Germain-en-Laye, Versailles and Corbeil. Belgium had more extensive routes than ours. However the lines of Rouen and Orleans were under construction and many others planned or in preparation. The public authorities, moreover, after the debates to which we have alluded above, had promulgated the famous law of 1842. It was evident that they opened brilliant prospects to engineers capable of resolutely entering into this new career. Louis Le Chatelier did not hesitate. He asked and he obtained in 1843 to pass in the service of the control, where he remained until 1845, occupied with the capital questions of layout, construction and exploitation. In the meantime, in 1844, he had received from the government of Louis-Philippe the mission of going to study the same questions on the spot, in Germany, which then had the advantage of having 2830 kilometers of railroads in operation. four times more than us.
The Chatelier brought back from this journey an extremely important work, nourished by facts and broad views. It appeared in 1845 under the title of Railways of Germany. It was of the most useful help to all the French engineers, who found there the complete description of the German network, and for each line, the system of execution, the route, the way, the stations, the material, the expenses of establishment , the farm and the product of the farm. This landmark work was a milestone in the career of its author who, in 1846, asked the mining administration for leave to take an active role as a railway engineer. It was for this reason that from 1846 to 1848 he was successively in charge of organizing the service of the equipment on the Northern Railway, then the exploitation and the traction on the railway of the Center Then he was in charge of prepare the way from Paris to Chartres.
At the same time, according to his constant habit of conducting head-on, with his main occupations, special works of different species and very absorbing, he made, with Ernest Gouin, the great builder who also belongs to the Eiffel Pantheon, interesting experiments on running locomotives. Its contributory part in this experimental research was exposed in a pamphlet published in 1849 under the title of Study on the stability of locomotive machines in motion. We can thus summarize the object of this study, so important for the exploitation of the railways, and in which Louis Le Chatelier has shown a rare sagacity of mind. It is known that in any machine in motion, the various parts which form it, independently of the external forces which are applied to the system, are subjected to mutual reactions due to the forces of inertia developed on all the material points whose motion is not currently rectilinear and uniform. It goes without saying that the force of inertia is generally greater, for a given material point, that its mass, speed and acceleration are all the greater. In particular, in a locomotive traveling in a uniform motion on a track, the material points which rotate with the axles of the wheels are all animated by a certain centrifugal force. All these forces do not cancel out if the axle axis is not a main axis of rotation through the center of gravity. On the other hand, the moving parts of a reciprocating movement, such as, for example, the piston and its stem, react on the button of the connecting rod that they drive, with a force varying in intensity and direction, according to the value and direction of their current acceleration. All these forces, due to inertia, variable from moment to moment in direction or magnitude, or both in size and in direction, can be calculated. It is thus recognized that in a locomotive going at high speed, they can take numerical values comparable to the external forces which are at stake on the machine.
Considered in their horizontal components and their vertical components, these forces are capable of giving couples tending to produce oscillations around three rectangular axes, one vertical, the other two horizontal, one parallel and the other transversal to the way. This is where parasitic movements, known as yaw, roll, and gallop movements, as well as variable pressures between the rails and wheel rims, result. Louis Chatelier tried to calculate the counterweights to fix on the wheels themselves, to make the effects of these contradictory forces disappear or lessen. He succeeded, to the great advantage of the smoothness of the machine's progress, as well as the preservation and uniformity of wear of the wheels of the machines and the rails of the track. The Chatelier is the first to be bound to this technical study in a special and thorough way. The practice of counterweight recommended by him, has been adopted in all countries of the globe. This invention popularized its name in both worlds. At the end of 1849 Le Chatelier was appointed to replace, in the direction of the control of the railways of the North, East and West. Bineau, who had just been appointed Minister of Public Works. He remained in office until May 21, 1850, when he became chief engineer of second class. In 1852 he was appointed a member of the Central Commission for Steam Engines. On June 1, 1855, he left the service of the administration and took a leave which was to extend until October 1, 1868. During the thirteen years of this interval, he devoted his life, in a very active way, to all the financial and technical enterprises which, under the impetus of the brothers Emile and Isaac Pereire, transformed the economic world and made the wealth and material power of France. He participated in all these beautiful works of canals, railways, roads, bridges, viaducts, cultivation of the Landes that have marked in France these prosperous years. At that time, he also belonged to the founding committee of the 19th century Encyclopedia, designed by the Pereire brothers, whose main members were Emile Augier, Baudrillart, Claude Bernard, Berthelot, Barral, Victor Duruy and Charles Duveyrier. , Hervé Faye, Jamin, Littre, Milne Edwards, Sainte-Beuve, Vacherot, Viollet-le-Duc, Zeller. The president was Michel Chevalier. Messrs. Emile and Isaac Pereire, who had put at the disposal of the work a million, had reserved the vice-presidency. Mr. Eugene Pereire, now president of the transatlantic company and son of Isaac Pereire, was the general secretary. The grand purpose of this project was this: "To expose how the various intellectual, moral, and material resources of modern society must be employed for the realization of the social progress which the human race has been pursuing for a century, and to establish the a record of the great conquests of science in all branches of the human mind. " One hundred volumes of the octavo format were to be devoted to this beautiful project. Priceless materials have been collected and discussed by all these luminaries of intelligence during nine years of diligent and regular preparatory work. The events, forever deplorable, of 1870 and 1871, put a sacrilegious and definitive obstacle to their glorious termination. Mr. Eugene Pereire has the famous debris. It is up to him to save from the nothing, for the greater good of humanity and for his own fame and that of his august parents, some of these precious manuscripts.
On the eve of the year 1870, all these affairs being finished or on the point of receiving a definitive solution, Louis Le Chatelier returned to the corps des mines, but without resuming the ordinary service. He was entrusted with a scientific mission, consisting in studying the processes then used in France and abroad for the steam-powered operation of locomotive machines, as well as the method due to M. Siemens for the direct production of the engine. steel and molten iron on the floor of a reverberatory furnace. The first idea, which has become simple and fruitful since it was finally elucidated by Le Chatelier, had remained, until then, full of obscurity and sterility. Here is what it consists of.
At all times, it was known that by reversing the admission into a locomotive machine in operation, the pistons, instead of receiving the engine work of the steam coming from the boiler, and then escaping to the chimney, sucked the air from the chimney and pushed back into the boiler, thus receiving a resistant work which came either on the slopes, deduction of the engine work of the gravity, or, when it was necessary to slow down or stop, attenuation of the half-force owned by the train. But with this system, we had a quick warm-up and seizing rubbing surfaces, a rapid increase in pressure in the boiler and soon the suspension of the injector Giffard serving food. The use of the reversal of the distribution was thus little practiced, never for a long time or in the normal circumstances, but at most accidentally, in some exceptional cases, for example when an unexpected obstacle appeared on the way, forcing the mechanic to use all his resources to stop his train as quickly as possible. Various means had been proposed to avoid these disadvantages in part. But none was satisfactory. The idea behind the backwash is essentially to bring, using pipes with faucets, to the base of the exhaust or the box of the drawer, a suitable mixture of water and steam coming from the boiler or, more simply, water from the boiler, which forms, in the exhaust pipe, returning to a pressure slightly higher than the atmospheric pressure, the indicated mixture. This idea belongs to Le Chatelier, who first experimentally demonstrated that the mixture of water and steam must be in the exhaust, in such quantity, that we see a plume of wet vapor coming out from above. the fireplace. It is certain then that the pistons aspire, not air, but an artificial atmosphere formed of supersaturated vapor, analogous to water spray. From then on, all the difficulties disappear. Today all the locomotives are equipped with this very simple device which puts in the hands of the mechanic a powerful means and always ready to moderate the speed in all circumstances. A diploma of honor awarded to Le Chatelier at the World Exhibition in Vienna in August 1873, came to definitively dedicate the high merit of this invention.
The process of Le Chatelier for the direct production of steel was attempted in France in the Fourchambault factories. It failed because, for the sake of economy, instead of defeating the siliceous bricks of England, bricks were taken that were not sufficiently refractory. The oven melted, the test was renewed under suitable conditions, and it succeeded completely.
On June 16, 1872, Louis Le Chatelier was appointed Inspector General in the mining corps. On the same date, he retired, motivated, not by fatigue and the need for rest, but by the deafness of which he was affected. This renunciation of the administrative service was for him the signal for new work in agronomy and chemistry, which death suddenly interrupted after a few months.
Louis Le Chatelier had a quick, practical, friendly spirit. From safe and delicate relationships, he was a faithful friend, a devoted colleague. Officer of the Legion of Honor and the Order of Leopold of Belgium, Commander of the Order of Charles III of Spain, Knight of the Order of Francis Joseph of Austria, Member of the Board of the Society of Encouragement for the National Industry, he was well suited to enter the Institute soon. His name was given to one of the streets of Paris, on the right bank of the Seine. His eulogy was written by Mr. Gallon, Inspector General of Mines, and inserted in the Annals of Mines. A speech was given on his grave, on the day of his funeral, by Mr. Gruner, Inspector General of Mines, and Mr. A. Ronna devoted a notice to him in the newspaper Le Temps of November 15, 1873.
The above portrait was made from a photograph provided by the family. Louis Le Chatelier has left a daughter and five sons, who are aptly named in the careers they have chosen.
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