Produced by Chris Curnow, Viv, Joseph Cooper and the Online Distributed Proofreading Team at http://www.pgdp.net [Transcriber's notes: 1) Peaucillier is a printers error and has been changed to Peaucellier. 2) The 4 characters at the end of the word 'Pafnutï[)i]' denote a letter 'i' with a breve accent.] CONTRIBUTIONS FROM THE MUSEUM OF HISTORY AND TECHNOLOGY PAPER 27 KINEMATICS OF MECHANISMS FROM THE TIME OF WATT _Eugene S. Ferguson_ JAMES WATT, KINEMATIC SYNTHESIST 187 TO DRAW A STRAIGHT LINE 199 SCHOLARS AND MACHINES 209 MECHANICIANS AND MECHANISMS 216 MECHANISMS IN AMERICA, 1875-1955 223 ADDITIONAL REFERENCES 229 KINEMATICS OF MECHANISMS FROM THE TIME OF WATT _In an inventive tour de force that seldom, if ever, has been equalled for its brilliance and far-reaching consequences, James Watt radically altered the steam engine not only by adding a separate condenser but by creating a whole new family of linkages. His approach was largely empirical, as we use the word today._ _This study suggests that, despite the glamor of today's sophisticated methods of calculation, a highly developed intuitive sense, reinforced by a knowledge of the past, is still indispensable to the design of successful mechanisms._ THE AUTHOR: _Eugene S. Ferguson, formerly curator of mechanical and civil engineering in the United States National Museum, Smithsonian Institution, is now professor of mechanical engineering at Iowa State University of Science and Technology._ In engineering schools today, a student is introduced to the kinematics of mechanisms by means of a course of kinematic analysis, which is concerned with principles underlying the motions occurring in mechanisms. These principles are demonstrated by a study of mechanisms already in existence, such as the linkage of a retractable landing gear, computing mechanisms, mechanisms used in an automobile, and the like. A systematic, if not rigorous, approach to the design of gears and cams also is usually presented in such a course. Until recently, however, no serious attempt was made to apply the principles developed in kinematic analysis to the more complex problem of kinematic synthesis of linkages. By kinematic synthesis is meant the designing of a linkage to produce a given series of motions for a particular purpose. That a rational--numerical or geometrical--approach to kinematic synthesis is possible is a relatively recent idea, not yet fully accepted; but it is this idea that is responsible for the intense scholarly interest in the kinematics of mechanisms that has occurred in this country within the last 10 years.