Dictionary of National Biography, 1885-1900/Barker, Thomas (1722-1809)
BARKER, THOMAS (1722–1809), scientific and miscellaneous writer, son of Samuel Barker the Hebraist [q. v.], was born at Lyndon, Rutland, in 1722. His principal work is ‘An Account of the Discoveries concerning Comets, with the way to find their Orbits, and some improvements in constructing and calculating their places; by T. B. Gent.,’ London, 1757, 4to. It contains a catalogue of the elements of the comets then known, and an explanation of Newton's problem of finding a comet's orbit from three observations; but the most valuable and original part is a ‘Table of the Parabola,’ for ascertaining any orbits which are approximately parabolic, and ‘for use in the parabolick motion of projectiles.’ This table was afterwards reprinted by Sir Henry C. Englefield in his work on the orbits of comets (1793), with special praise of the author's skill and industry.
Barker was for many years an assiduous observer of meteorological phenomena, his principal results being regularly registered in the ‘Philosophical Transactions’ of the Royal Society in which also appeared many other papers by him of a scientific nature. He also published three works in controversial theology, viz. 1. ‘A Treatise on the Duty of Baptism,’ London, 1771, 8vo. 2. ‘On Prophecies relating to the Messiah,’ London, 1780, 8vo. 3. ‘On the Nature and Circumstances of the Demoniacks in the Gospels,’ London, 1783, 8vo. Some of his views in this department are characterised in Nichols's ‘Literary Anecdotes’ as ‘sentiments not always orthodox or Calvinistic.’
It is specially remarked of Barker that though he lived to eighty-eight, he had from infancy subsisted entirely on a vegetable diet. He died at Lyndon on 29 Dec. 1809.
[Nichols's Literary Anecdotes, iii. 112 (note); Phil. Transactions, ix. 698, x. 645, xi. 432, 514, and xiii. 131, &c.; Sir H. C. Englefield's Orbits of Comets, note in Preface and table at end.]