C. Northcote Parkinson Martin's, Guernsey, where he purchased Les Caches Hall and later restored Annesville Manor. His writings from this period included a series of historical novels featuring a fictional naval officer from Guernsey, Richard Delancey, during the Napoleonic era. In 1969 he was invited to deliver the MacMillan Memorial Lecture to the Institution of Engineers and Shipbuilders in Scotland. He chose the subject 'The Status of the Engineer'. Parkinson's law, which provides insight into a primary barrier to efficient time management, states that, "work expands so as to fill the time available for its completion". This articulates a situation and an unexplained
Maupertuis's principle applied the principle only to light, not matter (see ). He arrived at the principle by considering Snell's law for the refraction of light, which Fermat had explained by Fermat's principle, that light follows the path of shortest "time", not distance. This troubled Maupertuis, since he felt that time and distance should be on an equal footing: "why should light prefer the path of shortest time over that of distance?" Accordingly, Maupertuis asserts with no further justification the principle of least action as equivalent but more fundamental than Fermat's principle, and uses it to derive Snell's law. Maupertuis specifically states