John Holwell
John Holwell (24 November 1649 – 1686?) was an English astrologer and mathematician. Biography. He was probably the John Holwell, son of Thomas and Catherine Holwell, who was baptised at St. James's, Clerkenwell, on 28 Nov, 1649. According to a biography, he was descended from the Holwells of Holwell House, near Tavistock, Devon, and his father and grandfather were engaged in Penruddock's plot in 1655, fell in the royalist cause, and as a consequence forfeited the family estates. It is known that a John Holwell of Sampford was actually sequestered in 1655, but in 1652 a Captain  John Holwell, probably the same person, appears as giving information against the papists to the officers of the Commonwealth, and there is no proof of his connection with Penruddock's plot. The same account states that after the Restoration, Holwell was made royal astronomer and surveyor of the crown lands, while his wife obtained a place at court, which is possible, and that he was preceptor to the Duke of Monmouth, which his age makes unlikely. He is further alleged to have written anonymously in support of the Exclusion Bill, and to have given such offence by his ‘"Catastrophe Mundi ’ that he was brought before the privy council, but to have defended himself so skilfully that no charge could be established against him. He usually described himself on the title-pages of his book as ‘philomath,’ and once as ‘teacher of the mathematicks and astrology’. In his advertisements (e.g. Catastrophe Mundi", p. 40) he announces that ‘Arts and Sciences are mathematically professed and taught by the author … at his house on the east side of Spittle Fields , over against Dorset Street … He also measureth building and surveyeth land for any later.for any man, having the mos experience in surveying of  any man in England.’ His writings show that he was a firm Protestant. The biography already referred to gives an unauthenticated story that in 1685 the government, fearing his pen, sent him to America to survey the town of New York, giving orders that he was not to be allowed to return. After completing, his work he died suddenly, it was suspected of poison. Holwell left a widow, by whom he had a son and a daughter. His son Zephaniah ("d." 1729) was a timber merchant in London, father of John Zephaniah Holwell. In the Bodleian Library  there is  a ‘Nativity of John Holwell’ (Ashm. MS. 240, f. 237 "b"), and a ‘Figure on the Nativity of John Holwell’ ("ib." 436, f. 75.)