Dictionary of National Biography, 1885-1900/Gascoigne, William (1612?-1644)
GASCOIGNE, WILLIAM (1612?–1644), inventor of the micrometer, son of Henry Gascoigne, esq., of Thorpe-on-the-Hill, in the parish of Rothwell, near Leeds, Yorkshire, by his first wife, Margaret Jane, daughter of William Cartwright, was born not later than 1612. He resided with his father at Middleton, near Leeds, and acquired a remarkable knowledge of astronomy. Charles Townley, writing to Ralph Thoresby 16 Jan. 1698–9, mentions that Gascoigne was a correspondent of Jeremiah Horrocks and William Crabtree, and adds: ‘It is to the mutual correspondence of this triumvirate that we owe the letters my brother Townley has of theirs, de re Astronomica. They are many and intricate, and he thinks not to be made use of, without particular hints or instructions from himself’ (Correspondence of Thoresby, i. 352). Gascoigne fell on the royalist side at the battle of Marston Moor on 2 July 1644. Aubrey's erroneous assertion (Lives of Eminent Men, p. 355), that at the time of his death he was ‘about the age of 24 or 25 at most,’ has been frequently repeated. Gascoigne left the manuscript of a treatise on optics ready for the press.
He invented methods of grinding glasses, and Sir Edward Sherburne states that he was the first who used two convex glasses in the telescope. When in 1666 Auzout announced his invention of the micrometer, Richard Townley, nephew of Christopher, presented Hook with a modification by himself of a similar instrument made by Gascoigne. A letter written by Crabtree to Horrocks in 1639 shows that Crabtree had seen Gascoigne use an instrument of the kind (Sherburne, Catalogue of Astronomers, pp. 92, 114). The instrument appears to have originally consisted either of two parallel wires or of two plates of metal placed in the focus of the eye-glass of a telescope, and capable of being moved so that the image of an object could be exactly comprehended between them. A scale served for the measurement of the angle subtended by the interval, and Gascoigne is said to have used this instrument for the purpose of measuring the diameters of the moon and planets, and also for determining the magnitudes or distances of terrestrial objects.
It is now generally admitted that Gascoigne was the original inventor of the wire micrometer, of its application to the telescope, and of the application of the telescope to the quadrant; though the invention was never promulgated, even in England, until the undoubtedly independent inventions of Auzout and Picard suggested its publication.
[Annual Register, iv. 196; Gent. Mag. ccxv. (1863), 760; Knight's Cyclopædia of Biography; Penny Cyclopædia; Phil. Trans. ii. 457, xlviii. 190; Taylor's Biog. Leodiensis, p. 86; Thoresby Correspondence, i. 349, 357, 387, ii. 302.]