David Gregory (physician)

David Gregory (20 December 1625 – 1720) was a Scottish physician and inventor. His surname is sometimes spelt as Gregorie, the original Scottish spelling. He inherited Kinnairdy Castle in 1664. Three of his twenty-nine children became mathematics professors. He is credited with inventing a military cannon that Isaac Newton described as "being destructive to the human species". Copies and details of the model no longer exist. Gregory's use of a barometer to predict farming-related weather conditions led him to be accused of witchcraft by Presbyterian ministers from Aberdeen, although he was never convicted.

Gregory, born on 20 December 1625, was the second-eldest son of John Gregorie (1598–1652), minister at the small parish village of Drumoak in Aberdeenshire, where Gregory was born. The family surname is sometimes spelt Gregorie, as in the original Scottish. His mother was Janet Anderson, whose father David was said to be exceptionally talented in the fields of medicine and mathematics. Gregory's younger brother was James Gregory, the designer of the Gregorian telescope.

Gregory's schooling was initially undertaken by his mother. His father then despatched him to the Netherlands to learn herring dealing, which was the predominant trade in Aberdeen. He returned to Aberdeen when he was in his early thirties in 1655 just after his father's death. Gregory had never been enthusiastic about trading and ceased trading as soon as he returned to Aberdeen to concentrate on scientific and literary topics. From 1663 until 1669 he was employed by Marischal College Library as a librarian. At that time he also furthered his scientific interests by writing to other overseas and British scientists.

In February 1655 Gregory married Jean Walker, with whom he had fifteen children. When his elder brother Alexander died childless in 1664, Gregory inherited Kinnairdy Castle, just south of Aberchirder, Banffshire. Alexander had been murdered. Jean Walker died in 1671 and Gregory remarried a few months later in early 1672. His second wife was Isabel Gordon. She bore him fourteen children. Twenty of his children reached adulthood and three, David (1659–1708), James (1666–1742) and Charles (1681–1754), were mathematics professors in the same period at British universities. David taught at the University of Oxford; James was based at Edinburgh University; and Charles at St Andrews.Thomas Reid was Gregory's grandson, as Reid's mother was Margaret, Gregory's daughter. Reid's father was Lewis Reid, a minister at Strachan, Aberdeenshire.

...
Wikipedia