The Mathematical Work of John Wallis
Wallis was one of the most original mathematicians of the seventeenth century and he left his mark on mathematics in many ways. He introduced arithmetical limits into mathematics (his famous infinite-product expression for $\\pi$ is an example). His researches (for example, the means whereby he obtained the aforementioned product) led directly to Newton's work on the binomial theorem and quadratures. He was the first to see the significance of fractional and negative exponents, and he is...
