What is John Playfair?
{{Infobox scientist | name = John Playfair | image = John Playfair by Sir Henry Raeburn.jpg | caption = John Playfair {{ndash}} Portrait by Henry Raeburn | birth_date = {{Birth date|1748|3|10|df=yes}} | birth_place = Angus | death_date = {{Death date and age|1819|7|20|1748|3|10|df=yes}} | death_place = }} '''John Playfair''' [[Royal Society of Edinburgh|FRSE]], [[Fellow of the Royal Society|FRS]] (10 March 1748 &ndash; 20 July 1819) was a Scottish scientist and mathematician, and a professor of [[natural philosophy]] at the [[University of Edinburgh]]. He is perhaps best known for his book ''Illustrations of the Huttonian Theory of the Earth'' (1802), which summarised the work of [[James Hutton]]. It was through this book that Hutton's principle of [[uniformitarianism]] first reached a wide audience. The idea was later taken up by [[Charles Lyell]] and [[Charles Darwin]]. Playfair is also remembered for his proposal of an alternative to [[Euclid]]'s [[parallel postulate]]. == Works == *1802: ''Illustrations of the Huttonian theory of the Earth''. *''Dissertation on the progress of Mathematical and Physical Science since the revival of learning in Europe'' in the [[Encyclopædia Britannica]] (Supplement to fourth, fifth and sixth editions). {{bio-stub}} {{authority control}} {{DEFAULTSORT:Playfair, John}} [[Category:1748 births]] [[Category:1819 deaths]] [[Category:Fellows of the Royal Society]] [[Category:Scottish mathematicians]] [[Category:Academics of the University of Edinburgh]]