David Gregory (physician) facts for kids
David Gregory (born December 20, 1625 – died 1720) was a smart Scottish doctor and inventor. His family name was sometimes spelled Gregorie, which was the old Scottish way. He became the owner of Kinnairdy Castle in 1664. David had many children, and three of them became famous math professors. He is known for inventing a special military cannon. The famous scientist Isaac Newton thought this cannon was "destructive to the human species." Sadly, no copies or details of this invention exist today. David also used a tool called a barometer to guess the weather for farming. Some church leaders in Aberdeen thought this was witchcraft, but he was never found guilty.
Early Life and Family
David Gregory was born on December 20, 1625. He was the second son of John Gregorie, a minister in the small village of Drumoak in Aberdeenshire, Scotland. His family name was sometimes spelled Gregorie, which was the original Scottish way. David's mother was Janet Anderson. Her father was known for being very good at medicine and mathematics. David's younger brother was James Gregory, who designed the Gregorian telescope.
David first learned from his mother at home. Later, his father sent him to the Netherlands to learn about herring dealing. This was a very important business in Aberdeen at the time. David returned to Aberdeen in 1655, when he was about 30 years old. This was just after his father had passed away. David was not very interested in trading. He stopped trading soon after he came back to Aberdeen. Instead, he focused on science and writing. From 1663 to 1669, he worked as a librarian at Marischal College Library. During this time, he also wrote letters to other scientists in Britain and overseas to learn more.
In February 1655, David married Jean Walker. They had fifteen children together. In 1664, his older brother Alexander passed away without children. David then inherited Kinnairdy Castle, which was south of Aberchirder, Banffshire. Jean Walker died in 1671. A few months later, in early 1672, David married again. His second wife was Isabel Gordon. They had fourteen children.
Twenty of David's children grew up to be adults. Three of his sons became mathematics professors at British universities during the same time. These were David (born 1659 – died 1708), James (born 1666 – died 1742), and Charles (born 1681 – died 1754). David taught at the University of Oxford. James worked at Edinburgh University. Charles taught at St Andrews. The famous philosopher Thomas Reid was David Gregory's grandson. Thomas Reid's mother was Margaret, David's daughter.
Life at Kinnairdy Castle
David Gregory moved to Kinnairdy Castle with his family in 1664. He inherited the castle and its lands from his older brother. This inheritance was very large and made him a rich man. Even though he did not know much about farming, he settled in well. He helped people in the area, both rich and poor, with his medical skills. He never asked for money for his medical advice.
David wrote letters to Edme Mariotte, a scientist who was also interested in atmospheric pressure. They both studied how to measure air pressure to predict the weather. David was even suspected of witchcraft because he could predict the weather so well. He explained that he used a barometer for his weather forecasting. This helped people understand his methods.
In 1690, David gave control of the castle and lands to his son David. His son was by then a professor of astronomy at Oxford University. This allowed David Gregory and his wife to move back to Aberdeen.
His Inventions and Later Years
David Gregory worked with a watchmaker from Aberdeen. Together, they started designing a military cannon. He showed the first model of this cannon to his son David. The model was then given to the famous scientist Isaac Newton. Newton advised that the model should be destroyed. David's grandson, Thomas Reid, later said that Newton believed the cannon was "destructive to the human species." Historians have not found any records or details about this special cannon model.
To avoid problems during the Jacobite Rebellion, David Gregory and his family moved back to the Netherlands in 1715. They returned to Aberdeen a few years later. David then worked on writing a journal, but it was never published. He passed away in 1720, at the age of ninety-five.
