# Mathematician:William Oughtred

## Mathematician

English mathematician credited with the invention of the slide rule.

Also credited with inventing a circular version although precedence for this was disputed with his student Richard Delamain.

Experimented with notations in his famously compact writings, inventing some new symbology which stuck, notably $\times$, $\sin$ and $\cos$.

Among others, he may have been influential in the introduction of the symbol $\pi$ for pi, using an abbreviation for the Greek word **periphery** (**περιφέρεια**).

His invention of $\times$ for multiplication came in for criticism from Leibniz for being too similar to the letter $x$. Leibniz's preference $\cdot$ is now widespread.

## Nationality

English

## History

- Born: 5 March 1574, Eton, Buckinghamshire, England
- Died: 30 June 1660, Albury, Surrey, England

## Publications

- 1631:
*Clavis Mathematicae* - 1632:
*Circles of Proportion and the Horizontal Instrument* - 1657:
*Trigonometrie*

## Sources

- John J. O'Connor and Edmund F. Robertson: "William Oughtred": MacTutor History of Mathematics archive

- 1986: David Wells:
*Curious and Interesting Numbers*... (previous) ... (next): A List of Mathematicians in Chronological Sequence - 1997: David Wells:
*Curious and Interesting Numbers*(2nd ed.) ... (previous) ... (next): A List of Mathematicians in Chronological Sequence - 2008: Ian Stewart:
*Taming the Infinite*... (previous) ... (next): Chapter $4$: Lure of the Unknown