Robertson, Abraham (DNB00)
ROBERTSON, ABRAHAM (1751–1826), astronomer and mathematician, son of Abraham Robertson, a man of humble station, was born at Dunse, Berwick, on 4 Nov. 1751. Robertson was educated at Westminster, and early in life kept a school at Ryle in Northumberland, and afterwards at Dunse. When about twenty-four he migrated to London, in the hope of obtaining a situation in the East Indies; but his patron died, and he was thrown on his own resources. Proceeding alone to Oxford, he met with great success, and was patronised by Dr. Smith, the Savilian professor of astronomy, and others. He matriculated from Christ Church on 7 Dec. 1775, graduated B.A. 1779, M.A. 1782, and took orders at Christmas 1782, in which year he obtained the chancellor's medal for an English essay on ‘Original Composition’ (Oxford English Prize Essays, 1836, vol. i.) He became one of the chaplains of Christ Church.
In 1784 Robertson succeeded Dr. Austin as lecturer for Dr. Smith, who was then acting as a physician at Cheltenham. On the death of the latter in 1797, Robertson took his place as Savilian professor of geometry. His lectures were clear, and he was always anxious to encourage his pupils. Thus he printed in 1804 a demonstration of Euclid V, Definition 5, for the benefit of beginners. In 1789 he was presented by the dean and canons of Christ Church to the vicarage of Ravensthorpe, near Northampton, but his principal residence was still in Oxford. In 1795 the Royal Society elected him a fellow. Robertson gave evidence before a committee of the House of Commons on the expediency of replacing London Bridge by a single arch (see the report published in 1801). In 1807 he was in London making calculations for Lord Grenville's system of finance, and in 1808 he drew up the tables for Spencer Perceval's system of increasing the sinking fund by granting life annuities on government security. He was made Savilian professor of astronomy from 1810. He died on 4 Dec. 1826 at the Radcliffe Observatory, Oxford, and was buried in the churchyard of St. Peter's-in-the-East. He married, about 1790, Miss Bacon of Drayton in Berkshire, who predeceased him. He had no children.
His chief work, dedicated to Dr. Cyril Jackson [q. v.], dean of Christ Church, was ‘Sectionum Conicarum Libri VII,’ 1792, with an exhaustive survey of the history of the study (see a review in the British Critic, 1792, p. 371). A shorter ‘Geometrical Treatise on Conics’ was published in 1802, which was still further abridged in ‘Elements of Conic Sections,’ 1818; 2nd edit. 1825. He made calculations for the Earl of Liverpool's ‘Coins of the Realm,’ 1805, and drew up an appendix on the relative values of gold and silver among the Persians, Greeks, and Romans. He also superintended the publication of the works of Archimedes, which were prepared for the press by Torelli, and of the second volume of Bradley's ‘Astronomical Observations,’ commenced by Dr. Thomas Hornsby (Greenwich Roy. Observ. Astron. Observations, 1st ser. vol. ii. 1798, &c.). The former was completed in 1792; the latter, a work of much labour, in 1805. There are five papers by Robertson in the ‘Philosophical Transactions:’ 1. ‘A Demonstration of the Binomial Theorem,’ 1795. 2. ‘A new Demonstration of the Binomial Theorem when the Exponent is a Fraction,’ 1806. 3. ‘On the Precession of the Equinoxes,’ 1807; ascribing previous errors to the crude state of the doctrine of compound rotatory motion; in 1808 Robertson published a ‘Reply to a Monthly and Critical Reviewer,’ in answer to strictures on this paper. 4. ‘A Direct Method of calculating the Eccentric from the Mean Anomaly,’ 1816. 5. ‘On Maskelyne's Formulæ for obtaining the Longitude and Latitude from the Right Ascension and Declination, and vice versa,’ 1816. Robertson wrote ‘A Concise Account of Logarithms’ (App. to Simson's ‘Euclid,’ 21st edit. 1825); and he contributed several papers to the first series of the ‘British Critic,’ and two to the ‘Edinburgh Philosophical Journal,’ 1822, viz. ‘Meteorological Observations made at the Radcliffe Observatory in 1816–21,’ and ‘On some Mistakes relating to Dr. Bradley's Astronomical Observations and Harriott's Manuscripts.’[Gent. Mag. 1827, i. 176; Biogr. Dict. Living Authors, 1816; Foster's Alumni Oxon.]