There was a vacancy there, because the sitting Member of Parliament George Rose had accepted an office under the Crown, and had to step down. Swinburne from 1786 had intended to stand for Northumberland, but Hugh Percy, 2nd Duke of Northumberland managed his selection for the Cornwall constituency. Swinburne completed the work on the north front of Capheaton Hall envisaged by his father.
lieutenant was carried out by William Newton.
He was a Fellow of the Royal Society, and Fellow of the Society of Antiquaries of London. He was a patron to William Mulready: they shared an enthusiasm for boxing.
Mulready taught the Swinburne family and painted their portraits. He also supported John Hodgson, who referred in his History of Northumberland to Swinburne as a "munificent contributor to the embellishments and materials of this work".
Their children were:
Edward (1788–1819), who married Anne Nassau Sutton;
Elizabeth (1790–1790);
Julia (since 1795);
Emily Elizabeth (since 1798), who married Henry George Ward in 1824;
Frances (1799–1821);
Elizabeth (1805–1896), married John William Bowden in 1828.
Royal Society; 16th Parliament of Great Britain]
He became Member of Parliament for Launceston in 1788.
