Night while observing satellites of Jupiter with his students by using telescopes, suddenly had a stroke and went blind. Studying Optiks and build telescopes are areas of concern.
However he had already begun work on an observatory.
The son of an Anglican priest, Gregory received his early education from his mother. On his death in MaidenheadBerkshire he was buried in Maidenhead churchyard. It is almost certain that it was through Moray that Charles II was persuaded to create the Regius Chair of Mathematics in St Andrews, principally to allow Gregory a position in which he could continue his outstanding mathematical research.
The book begins with 5 postulates and 37 definitions. In February he discovered Taylor series not published by Taylor untiland the theorem is contained in a letter sent to Collins on 15 February