Arthur Constantin Krebs (1850–1935): Engineer, Inventor and Industrial Leader
Arthur Constantin Krebs belonged to a remarkable generation of engineers whose achievements crossed the boundaries of several emerging technologies. During a career that extended from the military laboratories of the nineteenth century to the great automobile works of the early twentieth, he worked on balloons and powered airships, submarines, electric motors, fire-fighting equipment, motor vehicles and industrial organization. His appointment to the technical leadership of Panhard & Levassor after the death of Émile Levassor was therefore not the beginning of his engineering career, but the culmination of more than two decades of demanding mechanical and scientific work.
Krebs was a practical inventor who combined mathematical reasoning with an unusual ability to turn concepts into functioning machinery. At Panhard & Levassor he introduced improvements to steering, power transmission, ignition, engine design and manufacturing methods. Among these inventions, the automatic carburettor of 1902 deserves a particularly important place: it addressed one of the central practical problems of the early petrol engine, the regulation of the air–fuel mixture under changing operating conditions.
Family Background and Early Education
Arthur Constantin Krebs was born on 16 November 1850 at Vesoul, France. His family history reflected the political and military upheavals of the previous century. His grandfather Nikolaus Krebs, originally from Boppard in Germany, had served in Napoleon’s armies and had been seriously wounded during the Russian campaign of 1812. After settling in France, the family established connections with the circle of the former imperial administration. The name Constantin, which Arthur carried alongside his given name, recalled the family’s association with the Grand Duke Constantine.
As a child, Arthur displayed a persistent curiosity about mechanical devices. According to family recollections, he once dismantled his mother’s sewing machine in an attempt to construct a miniature sawmill. He read books on physics and mechanics and was especially impressed by the scientific writings of Adolphe Ganot. Technical drawing became one of his preferred methods of thinking: throughout his professional life, sketches and carefully executed plans often communicated his ideas more effectively than lengthy verbal explanations.
Krebs originally prepared to enter the École Polytechnique, but the Franco-Prussian War interrupted his studies. He joined the army in 1870, served as a junior officer and subsequently completed his military education at Saint-Cyr. Although his path differed from that of university-trained civilian engineers such as René Panhard and Émile Levassor, he continued to study mechanical science independently. The mixture of military discipline, experimentation and self-directed engineering would characterize his later work.
Military Engineering and the Airship La France
In 1877 Krebs was assigned to work on the military application of balloons. At Chalais-Meudon, near Paris, he helped organize a mechanical workshop dedicated to the construction of captive balloons, portable hydrogen-generating equipment and steam-powered handling machinery. His responsibilities embraced much more than the balloon envelope itself: every aspect of the supporting technology, from winches and generators to the control of complex mechanical apparatus, required careful study.
During his work at Chalais-Meudon, Krebs purchased a two-horsepower Otto four-stroke engine manufactured by Périn, Panhard & Cie for use in the balloon workshop. The acquisition created an unexpected early connection between the military engineer and the Parisian firm that he would later direct. It also introduced him to the practical limitations of contemporary internal-combustion engines. For the propulsion of an aircraft, available gas engines were still too heavy, leading him to investigate the use of electricity.
Working closely with Captain Charles Renard, Krebs participated in the design and construction of the electrically powered dirigible La France. He designed and built an electric motor of approximately eight horsepower operating at 1,200 revolutions per minute, together with lightweight mechanical components suited to the aircraft. The project required research into propulsion, aerodynamics, structures and electrical storage, at a time when each of these disciplines was still developing.
On 9 August 1884, with Krebs at the controls, La France completed a powered flight of approximately 7.6 kilometres and returned to its point of departure. This achievement was a landmark in controlled lighter-than-air flight: the airship did not simply drift with the wind, but demonstrated purposeful navigation and a return to its starting point. Subsequent flights reinforced the practical significance of the experiment. In 1886 Renard and Krebs jointly received the Ponti Prize of the Académie des Sciences for their progress in aerial navigation.
The Submarine Gymnote and Electrical Engineering
While the airship project was still fresh in public memory, Krebs became involved in an equally ambitious application of electrical propulsion: the experimental submarine Gymnote. The engineer Gustave Zédé invited him to develop the machinery and electrical systems required for the new craft. Temporarily assigned to naval work, Krebs prepared designs, organized manufacturing arrangements and supervised the construction of its power plant.
He developed an electric motor rated at approximately fifty-two horsepower, weighing about two tonnes. After trials of the machinery at Le Havre, Krebs participated in the submarine’s first tests at Toulon in November 1888. The vessel demonstrated that electrically driven underwater navigation could be controlled with increasing precision, even though underwater visibility and the determination of direction remained formidable problems.
Krebs addressed these problems by working on optical and gyroscopic apparatus. Together with Jean Rey, he developed an early submarine periscope, while his adaptation of a gyroscope provided a more stable directional reference than the magnetic compass in the iron hull. Such equipment should not be confused with the fully developed north-seeking gyrocompasses of the following century, but it belonged to the important early history of gyroscopic navigation. Gymnote remained in service as an experimental and training craft until 1907.
His activity in marine engineering continued into the 1890s. He worked on portable electrical motors, equipment for naval vessels and mechanisms intended for industrial use. These projects gave him a deep command of electrical machinery, motor control and materials, knowledge that would later influence several of his automobile inventions.
Reforming the Paris Fire Brigade
From 1884 to 1897 Krebs also served in the Paris Fire Brigade, eventually becoming its chief engineer. His assignment united the management of a public service with the design of new equipment. He travelled to London, Brussels, Amsterdam, The Hague, Berlin, Saint Petersburg, Moscow, Warsaw, Vienna and the United States to study fire-fighting arrangements, vehicle technology and the organization of emergency response.
Krebs brought a systematic approach to the modernization of the brigade. He studied the allocation of personnel, the distribution of alarm stations, communications, response equipment and the efficiency of the organization as a whole. His engineering work included signalling apparatus, electrical systems and ventilation equipment. In cooperation with the manufacturer Durenne, he also developed a steam-powered fire pump intended to combine efficient operation with reduced weight.
The significance of this work was institutional as well as mechanical. Krebs applied methods of observation, comparison and technical planning to a large organization whose effectiveness depended on coordinated action under pressure. The managerial experience he gained in this service would prove invaluable when he later assumed responsibility for a rapidly growing automobile manufacturer.
The Independent Automobile of 1896
Krebs’s interest in the automobile began before his appointment at Panhard & Levassor. By the early 1890s he was studying the adaptation of lightweight petrol engines to road transport. The Paris–Rouen trial of 1894 demonstrated the growing possibilities of the motorcar, and a journey to the United States in 1895 exposed him to the vigorous practical culture of American mechanical engineering.
In May 1896 he obtained a patent for a motor vehicle incorporating several original solutions. Its power unit and transmission were carried on a subsidiary frame supported at three points, an arrangement intended to isolate the mechanism from twisting of the chassis. Its steering geometry was calculated to encourage the wheels to return toward their straight-ahead position. These features reflected Krebs’s concern with stability, durability and the reduction of mechanical stress.
Electromagnetic Gear Selection
The most striking feature of his 1896 automobile was the electrically operated gear-changing system. Instead of relying exclusively on the physical engagement and disengagement of gear teeth, Krebs used electromagnets to select the required transmission ratio. The driver operated an electrical commutator, while magnetic clutches controlled the transmission of torque. The arrangement aimed to reduce the shocks and handling effort associated with early mechanical gearboxes.
This electromagnetic transmission was too unconventional to become the general pattern of contemporary automobiles, but it showed Krebs’s willingness to combine mechanical and electrical principles. His designs anticipated a recurring theme of automotive development: the use of electrical control to simplify tasks traditionally performed through direct mechanical manipulation.
On 3 September 1896 Krebs brought his automobile to the Panhard & Levassor works on avenue d’Ivry, where it attracted the attention of Émile Levassor. The ease with which the gears could be selected particularly impressed him. Levassor expressed interest in manufacturing the vehicle and in obtaining rights to the invention. From that moment the connection between Krebs and the firm became increasingly close.
The Successor to Émile Levassor
The death of Émile Levassor in 1897 confronted Panhard & Levassor with the need for a new technical leader. Krebs had already demonstrated exceptional ability in precisely those fields that the young automobile industry required: motors, transmissions, materials, electrical systems and the management of complex engineering projects. René Panhard therefore invited him to assume a leading role in the company.
Krebs later recalled that he left his military career to enter the automobile industry because its future seemed assured and the possibilities for engineering innovation were immense. On 27 January 1899, at the age of forty-eight, he became Managing Director. Together with the company’s designers and skilled workforce, he worked to improve vehicle quality and to expand manufacturing capacity without abandoning the technical standards on which the firm’s reputation rested.
Steering, Engines and the Development of the Motorcar
Krebs did not invent the steering wheel as such: wheel steering had appeared on automobiles before his time. His contribution was the practical introduction of an inclined steering wheel and an improved steering arrangement on Panhard & Levassor cars, notably in connection with the Paris–Amsterdam–Paris competition of 1898. These designs helped replace the tiller or steering lever with a control better suited to increasingly powerful and faster vehicles.
He also worked on self-centering steering geometry, reduction of unwanted steering reactions, engine balancing and improved transmission mechanisms. The combination of carefully designed steering linkages with controlled suspension and chassis flexing was essential to making the early automobile safer and less tiring to drive. As motorcars became heavier and faster, such refinements were no longer minor conveniences but necessary elements of their engineering.
Between 1897 and 1901 Krebs obtained twenty-four patents, including some related to woodworking machinery, a reminder of the company’s original industrial specialization. His subsequent work ranged across clutches, differentials, braking systems, water pumps, engine governors and ignition. The engineering office also developed engines using new materials and improved methods of manufacture, including the Centaure series. Improvements in engine balance and running speed allowed higher power without sacrificing the smoothness demanded by the company’s clientele.
Krebs contributed to the refinement of the gearbox, the use of stronger alloy steels, multi-disc clutch arrangements and dynamometer testing. His innovations were not isolated curiosities: they formed part of a sustained programme to improve the automobile as a complete and reliable machine. They also supported the continued success of Panhard & Levassor competition cars during a period when races provided especially severe tests of new designs.
The Automatic Carburettor of 1902
Among Krebs’s many automotive developments, the automatic carburettor patented in 1902 stands out as a particularly significant invention. The early petrol engine could operate satisfactorily at a restricted range of speeds, but supplying an appropriate mixture of fuel and air as speed and load changed presented considerable difficulties. Variations in the air flow through a conventional carburettor could cause the mixture to become excessively rich or lean, resulting in inefficient combustion, irregular operation and poor response to the driver.
Krebs sought a solution based on the pressure conditions within the induction system. His automatic carburettor combined a fuel-metering arrangement with auxiliary air passages governed by a diaphragm. As the depression in the intake changed, the diaphragm responded and controlled the admission of supplementary air. In this manner the carburettor could compensate for different operating conditions more effectively than simpler fixed arrangements. The objective was to maintain a sufficiently consistent relationship between air and petrol, while permitting the engine to vary its speed and power.
The distinctive diaphragm did not provide perfect mixture control under every imaginable condition, but the principle represented an important advance in automatic regulation. By adjusting supplementary air without requiring the driver to manipulate a separate mixture control continuously, the device made the engine more flexible and easier to operate, while potentially reducing unnecessary fuel consumption. The carburettor was adopted across the Panhard & Levassor range and attracted interest beyond the firm itself.
What makes Krebs’s work especially noteworthy is the method by which he approached the problem. In his testimony during the Selden automobile patent litigation in New York in 1906, he described the theoretical investigation that preceded the construction of his automatic carburettor. He maintained that the dimensions calculated for the initial apparatus gave the expected results at the first trial, without extensive trial-and-error modification. The testimony provides a valuable contemporary account of a designer seeking to apply mathematical analysis to a difficult practical problem of internal-combustion engineering.
The Krebs carburettor was part of a broader programme of engine regulation that also included work on intake-valve control, governors and ignition. During the following years he continued to investigate petrol engines for applications beyond the automobile, including submarines and dirigibles. His interests remained those of a general mechanical engineer rather than an inventor confined to a single product.
Further Innovations: Testing, Transmission and Engine Design
Krebs also investigated the accurate measurement of engine output. His work on electrical dynamometer brakes made it easier to test increasingly powerful engines under controlled conditions, an important prerequisite for the systematic improvement of their performance. In chassis engineering he developed refinements to shock absorption, braking and clutch mechanisms, while the company investigated stronger steels and new forms of coupling between rotating shafts. Among the later inventions associated with his work was the elastic coupling known as the Flector, developed in 1911, intended to transmit torque while accommodating small misalignments and reducing shocks and vibration.
Nor did Krebs limit his attention to conventional valve-operated petrol engines. Under his technical direction Panhard & Levassor developed its own versions of the Knight sleeve-valve engine, while the engineering department continued working on improved cylinders, water cooling, lubrication, differentials and transmission units. These projects reveal the range of Krebs’s interests: rather than concentrating on a single invention, he sought to improve the automobile through coordinated advances in materials, power transmission, engine performance and manufacturing precision.
Arthur Krebs and Charles de Fréminville
In March 1899 Krebs brought Charles de Fréminville into Panhard & Levassor as his assistant. Born in 1856, de Fréminville had graduated from the École Centrale in 1878 and had acquired extensive experience in railway engineering, including the study of equipment and rolling stock in Britain and the United States. The two men already knew one another well: in 1885 they had travelled together to America to study fire-fighting technology, and they were also connected by family ties, since Krebs had married Marie de Fréminville, Charles’s sister.
De Fréminville rose through the company to become Technical Director and Deputy Managing Director. He was particularly interested in the quality of metals, precision manufacturing and the organization of industrial work. Together, the two engineers formed a leadership team whose authority rested less on family ownership than on technical and managerial competence. Under their direction the company continued to develop its designs and expand its output.
For the financial year ending in September 1899, the company’s sales approached seven million francs, with reported net profits exceeding 2.5 million francs; production was approximately 450 motorcars and the workforce numbered around 950. These figures illustrate both the company’s early commercial success and the small scale of automobile manufacturing before the emergence of true mass production.
The End of the Belle Époque: Luxury versus Mass Production
At the turn of the century, Panhard & Levassor occupied a prestigious position in the automobile world. Its cars had won major early competitions, and wealthy buyers valued their quality and reputation. Yet this advantage became a strategic constraint. In 1901 the Board adopted the principle that the company should concentrate on expensive automobiles for affluent customers. Such a policy could produce impressive margins but was increasingly at odds with the rapid transformation of the market.
New manufacturers, including Renault, Peugeot, Mors, Darracq and De Dion-Bouton, challenged the established pioneers. Competition intensified, and the American financial crisis of 1907 further weakened demand. Panhard & Levassor eventually had to reduce its workforce and reconsider its reliance on luxury automobiles. Meanwhile, Ford and other American manufacturers were demonstrating the potential of simplified model ranges, standardized parts and much larger production runs.
Krebs and de Fréminville believed that industrial survival required a fundamental reorganization: fewer different models, more rigorous standardization and the development of affordable automobiles. In a report of January 1912, Krebs argued that modern manufacturing demanded precise components and close coordination between engineers and workers, and that economy depended upon production in substantial quantities with a minimum of model variation.
The company nonetheless remained divided. René de Knyff, a celebrated former Panhard racing driver and influential administrator, favored the continuation of prestigious sporting and luxury vehicles. The extravagant Skiff automobiles exemplified the exclusive character of part of the firm’s output, while Krebs advocated broader demand through a relatively inexpensive 10 h.p. chassis. The affordable model introduced in 1912 remained in production into the following decade, but volumes were modest by the standards then emerging in America.
These disagreements were not merely matters of taste. They reflected fundamentally different views of the automobile industry: one saw automobiles primarily as expensive objects for individual purchasers; the other understood them increasingly as standardized industrial products. The engineers who directed the workshops could propose technical and organizational changes, but the final authority lay with the Board and the shareholders.
The First World War and Departure from Panhard & Levassor
With the outbreak of war in 1914, industrial priorities changed dramatically. Krebs took part in redirecting the resources of Panhard & Levassor towards military requirements, drawing upon his long experience in mechanical and military engineering. The company’s workshops and engineering staff became part of the wider French war effort.
After prolonged disagreements over the future of production and organization, Charles de Fréminville departed from the company. Krebs resigned his directorship in 1916, though he continued for a time as an engineering adviser. His departure marked the end of almost two decades of direct responsibility for one of the most influential automobile manufacturers of the pioneering period.
Later Life and Historical Legacy
Krebs lived until 1935, long enough to see the automobile become an established element of modern life and powered flight develop far beyond the experiments at Chalais-Meudon. In his later years his technical achievements continued to be commemorated, including at the fiftieth anniversary of the flights of La France. He was made a Commander of the Legion of Honour in the final year of his life, a recognition of the breadth of his public and engineering service. He died in Quimperlé in March 1935.
The range of his achievements is exceptional. In aeronautics, he helped demonstrate controlled powered flight; in naval engineering, he designed electrical machinery and early submarine navigation apparatus; in the Paris Fire Brigade, he reorganized equipment and operations; and in automobile engineering, he developed important solutions for steering, transmissions, engine regulation and industrial management. The automatic carburettor of 1902 remains a particularly clear example of his ability to use scientific reasoning to resolve a practical mechanical problem.
Arthur Constantin Krebs should therefore be remembered not simply as the successor of Émile Levassor, but as one of the versatile engineers who linked the experimental technologies of the nineteenth century with the industrial systems of the twentieth. His career illustrates how progress in the early automobile industry depended upon knowledge acquired in many different fields—and how the ability to organize production could be as decisive as the invention of a new mechanism.
Selected Historical Sources
Vladimir Vershinin, Panhard & Levassor, sections on Arthur Constantin Krebs and the early automobile industry.
Arthur C. Krebs, testimony in the Selden patent litigation, New York, 1906.
Wikimedia Commons: Arthur Constantin Krebs — historical photographs, patents, drawings and archival documents.