Background
Donn was born at Bideford, Devon, where his father and brother Abraham (1718–1746) kept a school.
Donn was born at Bideford, Devon, where his father and brother Abraham (1718–1746) kept a school.
Until 1768 he was a ‘teacher of the mathematics and natural philosophy on the Newtonian principles’ in his native town. In 1768 he was elected librarian of the Bristol Library, and had fruitless plans converting it into a mathematical academy. In addition to his school he gave a course of fourteen lectures in experimental philosophy to subscribers at one guinea each.
These lectures he continued to deliver when he left Bristol for Kingston near Taunton.
But then he delivered them in the Christmas or midsummer vacation. He would travel thirty miles for twenty subscribers, or fifty miles for thirty subscribers.
By 1775 he was settled at Kingston. Towards the end of his life he was appointed master of mechanics to the king, on the death of Anthony Shepherd.
He died in June 1798.
Donn mentions in his Mathematical Tables, 1789, that he has added a final e to his name. But on the title-page the name is spelt Donn.