Philippe de La Hire : un astronome novateur dans la gnomonique et les astrolabes

Abstract

Philippe La Hire’s major work on sundials was a break with the traditional treatment that was reserved for them for their construction. His method consists of drawing any type of sundial and setting up the polar style, only by geometry, knowing only the date. This search for universality in the methods of making scientific instruments is also found in La Hire’s research on the astrolabe ; although at the end of the 18th century the astrolabe fell into disuse, La Hire developed a new type of projection which made this tool valid in all latitudes. This La Hire research takes more mathematical tests than pragmatic propositions.