James Bradley

James Bradley was an English astronomer and priest who served as the third Astronomer Royal from 1742, born at Sherborne near Cheltenham in Gloucestershire; he died in 1762. He is best known for two fundamental discoveries, the aberration of light, made between 1725 and 1728 while he was attempting to detect stellar parallax, and the nutation of the Earth's axis, found between 1728 and 1748, which the historian Delambre called the most brilliant and useful discoveries of the century. After Westwood's Grammar School at Northleach he entered Balliol College, Oxford, in 1711, made his early observations at the rectory of Wanstead under his uncle James Pound, and was elected a fellow of the Royal Society on 6 November 1718. He became vicar of Bridstow in 1719 and resigned his church preferments in 1721 when he was appointed to the Savilian chair of astronomy at Oxford, and as reader on experimental philosophy from 1729 to 1760 he delivered 79 courses of lectures at the Ashmolean Museum. In 1742 he succeeded Edmond Halley as Astronomer Royal and, with an eight-foot quadrant completed by John Bird in 1750, accumulated at Greenwich ten years of observations. He retired in broken health to Chalford in Gloucestershire.