Profession: Mathematician and Cryptographer
Biography: John Wallis was the most important English Mathematician until Isaac Newton, and was himself an influence on Newton's work.
As a result of Wallis' work "Arithmetica Infinitorum" (1656) he is given partial credit for the development of infinitesimal calculus.
In his work on conic sections "De Sectionibus Conicis" (1656) Wallis introduced the symbol ∞ for infinity and similarly used 1/∞ for an infinitesimal. His "A Treatise of Algebra" (1685) was the first history of mathematics in the English language.
Wallis also served as chief cryptographer for Parliament between 1643 and 1689 and later to the royal court.
- 1649-10-31 John Wallis, newly appointed Savilian Professorof Geometry at Oxford University, gives his Inaugural lecture
- 1663-07-11 Oxford mathematician John Wallis gives a lecture on Euclid’s parallel postulate, first Western attempt to derive the parallel postulate as a theorem