# Mathematician:William Jones

## Mathematician

Welsh mathematician who has recently come to notice for being the first to use the symbol $\pi$ (pi) in print to represent the ratio of the circumference of a circle to its diameter.

Close friend of Isaac Newton and Edmund Halley.

On his death, left behind him a library of about $15 \, 000$ books, which was probably the most valuable library of mathematics in England. This has only recently been fully dispersed.

## Nationality

Welsh

## History

- Born: 1675 in Llanfihangel Tre'r Beirdd, Isle of Anglesey
- 1695 -- 1702: Served at sea, teaching mathematics on board Navy ships
- 1702: Started a career lecturing on mathematics in coffee-houses
- November 1711: Became a Fellow of the Royal Society, later its president
- Died: 3 July 1749 in London, England

## Inventions

- The symbol $\pi$ (pi) for the ratio of the circumference of a circle to its diameter

## Publications

- 1702:
*A New Compendium of the Whole Art of Navigation* - 1706:
*Synopsis Palmariorum Matheseos*in which $\pi$ (pi) first appeared in print - 1711:
*Analysis per quantitatum series, fluxiones ac differentias* - 1731:
*Discourses of the Natural Philosophy of the Elements*