C. Northcote Parkinson C. Northcote Parkinson Cyril Northcote Parkinson (30 July 1909 – 9 March 1993) was a British naval historian and author of some 60 books, the most famous of which was his best-seller "Parkinson's Law" (1957), in which Parkinson advanced Parkinson's law, stating that "work expands so as to fill the time available for its completion", an insight which led him to be regarded as an important scholar in public administration and management. The youngest son of William Edward Parkinson (1871–1927), an art master at North East County School and from 1913 principal of York School of Arts and Crafts, and
Virtual work statics. Working with Leibnizian concepts, Johann Bernoulli systematized the virtual work principle and made explicit the concept of infinitesimal displacement. He was able to solve problems for both rigid bodies as well as fluids. Bernoulli's version of virtual work law appeared in his letter to Pierre Varignon in 1715, which was later published in Varignon's second volume of "Nouvelle mécanique ou Statique" in 1725. This formulation of the principle is today known as the principle of virtual velocities and is commonly considered as the prototype of the contemporary virtual work principles. In 1743 D'Alembert published his "Traité de Dynamique" where