by H. K. Higton

© Oxford University Press 2004 All rights reserved

**Delamain, Richard, the elder** *(d.* 1644?), mathematician, began his career as master of a writing-school in Drury Lane in the early 1620s, according to William Oughtred (Oughtred, sig. B2, recto). At the same time he attended lectures at Gresham College, thus gaining a knowledge of mathematics. He referred to Edmund Gunter (who resided in London from 1615 to his death in 1626) as his tutor, and was taught astronomy by Oughtred. He established himself as a mathematics teacher during the late 1620s. Nothing is known of his birth, origins, and early life.

In 1629 Delamain sent the manuscript of *Grammelogia, or, The Mathematical Ring* to Charles I, together with the instrument, a circular slide rule. The king granted him a monopoly on the instrument and the book was published in January 1631. In the same year Delamain produced *The Making, Description and Use of ... a Horizontall Quadrant,* which described an instrument inscribed with a projection of the celestial sphere onto the plane of the horizon. These books involved him in a bitter dispute with Oughtred, who claimed both instruments as his invention, saying that Delamain had stolen the designs.

On 4 March 1633 a royal warrant was issued granting Delamain the right to teach the use of his ring and all other mathematical instruments in London and elsewhere. He was also employed for £40 a year as quartermaster-general and tutor to the king. He worked on surveying forts and castles with Sir John Heydon, the master of the ordnance, but petitions for a position as royal engineer were unsuccessful. Delamain was commissioned by the king to oversee the making of a number of instruments, including a 'great Octans', and a 'great Universal Concave' (perhaps the concave dial at Whitehall), besides pieces for the king's bedchamber and the 'Great Ship'. It is probable that the silver sundial sent to the duke of York by the king just before his death was one of Delamain's horizontal quadrants.

At some time in the early 1620s Delamain married Sarah *(d.* in or after 1645); they had at least eleven children, of whom four attended the Merchant Taylors' School. The clergyman Richard Delamaine the younger *(bap.* 1627, *d.* 1657) and the Muggletonian Alexander Delamaine *(bap.* 1631, *d.* 1685) were his sons. Delamain was still working for the king early in 1644 but presumably died shortly thereafter, since his widow petitioned the House of Lords for relief the following year.

H. K. HIGTON

**Sources **

E. G. R. Taylor, *The mathematical practitioners of Tudor and Stuart England* (1954)

*CSP dom., 1629-45*

W. Oughtred, *The circles of proportion and the horizontal instrument,* trans. W. Forster, another edn (1633)

R. Delamain, *Grammelogia, or, The mathematical ring* (1631)

*Lords journals,* 1645

Wood, *Ath. Oxon.*

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