John Machin (bapt. c. 1686 – June 9, 1751) was a professor of astronomy at Gresham College, London.He is best known for developing a quickly converging series for pi in 1706 and using it to compute pi to 100 decimal places.
Origin. The family descended from Theobald Walter (d. 1205), eldest son of Hervey Walter and Maud de Valoignes. During the reign of Henry II of England Theobald held the position of pincerna (Latin) or boteillier (Norman French), the ceremonial cup-bearer or butler to Prince John, Lord of Ireland.