In 1697, he was appointed headmaster of his old school,
Derby, and lecturer of All Saints' Church,
Derby. He was Vicar of
Elvaston, Derbyshire, from 1699 until 1723. In 1706, he published an edition of the verse of the
Greek poet
Theognis, with a translation into
Latin. His next book,
An Introduction to the Classics (1718), was written for schoolboys and had numerous editions. It was revised by
William Fordyce Mavor as ''Blackwall's Introduction to the Classics'' in 1809. In 1722, he became headmaster of the Grammar School at
Market Bosworth,
Leicestershire, and enlarged it. He was Rector of
Clapham from 1726 until his death. At both his schools Blackwall taught from his own Latin grammar, which he eventually published anonymously in 1728 as
A new Latin Grammar: being a short, clear, and easy introduction of young scholars to the knowledge of the Latin tongue. Blackwall's last work was
The Sacred Classics Defended and Illustrated, or, An essay humbly offered towards proving the purity, propriety, and true eloquence of the writers of the New Testament (1725). ==Family==