William Crabtree

William Crabtree was an English astronomer, mathematician and merchant from Broughton in Lancashire, born in 1610 and dying in 1644, one of only two people to observe and record the first predicted transit of Venus, in 1639. Educated at Manchester Grammar School, he married into a wealthy family and worked as a merchant in Manchester, devoting his spare time to astronomy, measuring the movements of the planets and making careful calculations, with which he rewrote the existing Rudolphine Tables of planetary positions. He corresponded with Jeremiah Horrocks from 1636, and a group of northern English astronomers that included William Gascoigne, who called themselves the Keplerians, formed around them as Britain's first followers of Kepler. Crabtree's calculations were crucial in allowing Horrocks to estimate the size of Venus and the distance from the Earth to the Sun. He made his will in July 1644 and was buried at Manchester Collegiate Church.