c. 1612-1644

English astronomer who introduced telescopic sights and invented the first micrometer for measuring small angular distances at a telescope's focal point. Gascoigne produced a working model by 1641 but had little time to promulgate his ideas due to his untimely death in the royalist disaster at Marston Moor during the English Civil War. The micrometer and telescopic sight only saw widespread application after Adrian Auzout and Jean Picard duplicated Gascoigne's work in the late 1660s.