onstrated 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.

This scholarly activity has resulted in the rediscovery of many earlier
works on the subject, and nearly all the scholars now working in this
field have acknowledged in one way or another their debt to those who
arrived on the scene at an earlier time than they. There have been
occasional reviews of the sequence and nature of developments, but the
emphasis naturally has been upon the recent past. It seems to me that
there is something to be gained in looking beyond our own generation, or
even beyond the time of Franz Reuleaux (1829-1905), who is generally
credited with originating many of our modern concepts of mechanism
analysis and design, and to inquire into the ideas that made possible
Reuleaux's contributions.

_Take to Kinematics. It will repay you. It is more fecund than
geometry; it adds a fourth dimension to space._

--Chebyshev to Sylvester, 1873

While no pretense of completeness is made, I have tried in this paper to
trace the high points in the development of kinematic analysis and
synthesis, both in academic circles and in the workshop, noting where
possible the influence of one upon the other. If I have devoted more
space to particular people and episodes than is warranted by their
contributions to the modern treatment of the subject, it is because I
have found that the history of kinematics of mechanisms, like the
history of any other branch of engineering, is more interesting and more
plausible if it is recognized that its evolutionary development is the
result of human activity. This history was wrough