Franz Reuleaux was a prominent Prussian mechanical engineer. Reuleaux was significant in engineering as the founder of modern kinematics and was recognized in Germany as the spokesman for engineers and for modern technology in general during the first two decades of the Second Empire, a period of rapid industrial growth.
Background
Franz Reuleaux was born on September 30, 1829, in Eschweiler, Prussia (now part of Germany). Reuleaux was the fourth son of Johann Josef Reuleaux, one of the first steam engine manufacturers in the Rhineland and himself the son of a master engineer (Kunstmeister ) from Liège.
Education
The elder Reuleaux died when Franz was a child, and in 1839 his widow moved the family to Koblenz, where Franz attended school through the intermediate grades. In 1850 he enrolled at the Karlsruhe Polytechnische Schule, where he studied for two years under Redtenbacher, one of the foremost engineering teachers of the day.
In 1852 and 1853 Reuleaux studied at the universities of Berlin and Bonn, where, besides attending lectures on science, mathematics, and philosophy, he wrote, in collaboration with a fellow student, C. L. Moll, a brief treatise on the strength of materials and a long handbook of machine design.
Career
In 1846 Reuleaux joined his father’s factory at Eschweiler, now run by an uncle, first as a draftsman and later (1848) as a field engineer.
In 1856 Reuleaux was named professor of machine design at the newly founded Swiss Federal Polytechnical Institute. After eight years in Zurich, he became a professor of mechanical engineering at the Gewerbe Institut in Rerun in 1864; he served as director of that school from 1867 until, after merging with the Berlin Bauakademie, it was reorganized in 1879 into the Technische Hochschule at Charlottenburg. He was elected rector of the institution for several terms. He retired from teaching in 1896 and remained in Berlin until his death.
Reuleaux’s basic field was machine design. Besides a great number of minor publications on all aspects of this field, he wrote a handbook of machine design, Der Constructeur, highly popular at the time but later denounced as “a technological recipe book” (R. von Mises, 1929). Within the general field of machine design, he discovered his own specialty in kinematics, with which his name is now permanently linked. Reuleaux had planned an exhaustive treatment of kinematics. The highly successful first volume on theoretical kinematics appeared in 1875; but a second volume, on the more technical and practical aspects. was published when Reuleaux’s influence was waning (1900) and received less notice. A projected third volume was never written.
The first volume, which had the greatest impact, is not an engineering book in the modern sense. Reuleaux saw its strongest points in logic and philosophy. Its subtitle, Gründzuge einer Theorie des Maschinenwesens, suggests the breadth of its ambitions. The volume consists of three parts. The first, in the tradition of Kachette, Borgnis, and Babbage, provides the logical and conceptual tools for analyzing and classifying machinery; prominent among them are the concepts of the kinematic pair and the kinematic chain, and a symbolic notation which Reuleaux hoped to employ algebraically in synthesizing mechanisms.
The second part was devoted to the application of this conceptual apparatus to the task of “kinematic analysis,” which consisted of breaking down given machines into chains of abstract components in order to identify mechanisms that were kinematically equivalent. The third and shortest section is hardly more than a veiled admission of failure in attaining its declared objective of “kinematic synthesis” by means of systematic-deductive methods.
Although falling short of its objectives, Reuleaux’s kinematics was studied eagerly. It not only led to the cultivation of kinematics as an independent discipline but also became particularly popular among nontechnical readers. When its fatal weakness, a total disregard for dynamic phenomena. was recognized, the reaction was strong enough to cause kinematics to he struck from the Berlin curriculum after Reuleaux’s retirement. Reuleaux’s system of classifying mechanisms, however, proved definitive; and modern kinematics acknowledges a large debt to him.
Reuleaux affected German engineering and industry by means other than his books. He corresponded with leading industrialists, such as Eugen Langen, who valued his advice: he had an important role in the founding of the Mannesmann steelworks; he worked hard for the passage of comprehensive German patent legislation. Of special interest to him were world exhibitions. He was a member of the juries of the expositions at Paris (1867), Vienna (1873), and Philadelphia (1876); and he also served as the German commissioner at Philadelphia, Sydney (1879), and Melbourne (1881).
Reuleaux was a prolific writer and covered a broad spectrum. He wrote not only on all aspects of engineering but also on technology and civilization (translation in the 1890 Report of the Board of Regents of the Smithsonian Institution ), on the purity of the German language, and on technology and art; he also published a number of travel journals and a translation into German, in the original meter, of Longfellow’s Hiawatha.
After enjoying great prestige in the 1870s and 1880s, Reuleaux saw his influence decline. A younger and scientifically more refined generation of engineers recognized the weaknesses of his technical teachings, weaknesses amplified by the all-too-broad scope of his interests and his love of bold formulation. The dominance of kinematics had to give way to a fuller consideration of dynamic problems.
A controversy arose among academic engineers, the opposing parties being identified by their espousal of theory and of practice. The proponents of “practice” eventually gained control of most German institutes of technology, while Reuleaux, a prominent “theorist,” spent his later years, especially after retirement, in increasing isolation.
Membership
Franz Reuleaux was a member of the Royal Swedish Academy of Sciences from 1882.