The book presents a history of classical mechanics by focusing on issues
of equilibrium. The historical point of view adopted here restricts
attention to cases where the effectiveness of forces is assessed on the
basis of the virtual motion of their points of application. For
completeness, hints of the alternative approach are also referred, the
Archimedean for ancient mechanics and the Newtonian for modern
mechanics. The laws resulting from consideration of virtual motions are
named laws of virtual work. The modern formulations of the principle of
virtual work are only a particular form of them.
The book begins with the first documented formulations of laws of
virtual work in the IV century BC in Greece and proceeds to the end of
the XIX century AD in Europe. A significant space is devoted to Arabic
and Latin mechanics of Middle Ages. With the Renaissance it began to
appear slightly different wordings of the laws, which were often
proposed as unique principles of statics. The process reached its apex
with Bernoulli and Lagrange in the XVIII century. The book ends with
some chapters dealing with the discussions that took place in the French
school on the role of the Lagrangian version of the law of virtual work
and its applications to continuum mechanics.