James Gregory

James Gregory, who lived from 1638 to 1675, was a Scottish mathematician and astronomer, born in the manse at Drumoak in Aberdeenshire and first taught geometry by his mother. He studied at Marischal College, went to the University of Padua in 1664 where he was taught by Stefano Angeli, and published Vera circuli et hyperbolae quadratura in 1667 and Geometriae pars universalis in 1668, the latter giving the first published statement and proof of the fundamental theorem of the calculus in a geometric form. His Optica Promota of 1663 described the reflecting telescope now called the Gregorian telescope, and the use of the transit of Venus to measure the distance of the Earth from the Sun. He also made advances in trigonometry, discovering infinite series representations for several trigonometric functions. Elected a Fellow of the Royal Society in 1668, he became the first Regius Professor of Mathematics at the University of St Andrews, where in 1673 he laid a meridian line across the floor of his lab, and was later professor at the University of Edinburgh. He suffered a stroke while viewing the moons of Jupiter with his students and died a few days later at the age of 36.