new useful mechanisms. At the expense of the German government, he directed the design and manufacture of over 300 beautiful models of simple mechanisms, such as the four-bar linkage and the crank. These were sold to universities for pedagogical purposes. Today, the most complete set are at Cornell University College of Engineering. Using his notation and methods for systematically varying the elements (e.g. inversions, changing relative sizes of the links, etc.) he showed how the four-bar linkage could be mutated into 54 mechanisms, which fall within 12 classes. Books by Franz Reuleaux Kinematics of Machinery (1875), ebook The Constructor (1861), ebook Kurzgefasste Geschichte der Dampfmaschine (1891) Thomassche Rechenmaschine (2d ed. 1892) Notes References Bragastini, Roberto Contributo per una interpretazione filosofica dell'opera di Franz Reuleaux, Università degli Studi di Milano (Milan, 2003). Moon, Francis "Franz Reuleaux: Contributions to 19th Century Kinematics and Theory of Machines". Further reading External links Kinematic Models for Design Digital Library (KMODDL) Movies and photos of hundreds of working mechanical-systems models at Cornell University. Also includes an e-book library of classic texts on mechanical design and engineering. Reproductions of Franz Reuleaux's Kinematic Models Modern reproductions of the kinematic models as originally produced. 1829 births 1905 deaths People from Eschweiler German mechanical engineers Members of the Royal Swedish Academy of Sciences Academic staff of ETH Zurich Engineers from North Rhine-Westphalia