WHEN the earl was confined to the Tower through the complicity of some of his family in the Gunpowder Plot,* Harriot and two other mathematical worthies, Robert Hues and Walter Warner,* often bore him company. They were known as “the three magi.” Harriot appears to have passed an uneventful life, and at his death was buried in St Christopher’s Church, on the site of which now stands the Bank of England. A monument erected to his memory was destroyed in the Great Fire of 1666.
As an algebraist Harriot is a connecting link between Vieta and Descartes.* His “Artis Analyticae Praxis” was not published until ten years after his death. The revival of his fame as an astronomer was due to von Zach,* who, while on a visit to the Earl of Egremont in 1784,* discovered some of Harriot’s writings beneath a pile of old stable accounts at Petworth Castle;* while the reduction of Harriot’s observations of the comet of 1607 formed one of the first tasks of Bessel’s astronomical career. Some of Harriot’s manuscripts are in the British Museum.
* See Gunpowder, Treason and Plot. One of the five conspirators was Thomas Percy (?1560-1605), cousin to Henry Percy (1564-1632), 9th Earl of Northumberland. Thomas, who was based at Syon House and collected the rents, was shot dead while on the run with leader Robert Catesby; indeed, they were taken down together with one and the same shot. Henry was accused of misprision (failing to alert the authorities to a crime) but the charge was dropped owing to lack of evidence.
* Robert Hues (1553–1632), corrected from ‘Thomas Hughes’; and Walter Warner (1563–1643).
* François Viète, Seigneur de la Bigotière, Latinised to Franciscus Vieta (1540-1603), a French mathematician who made important contributions to algebra including the use of letters; and René Descartes (1596–1650), a Franco-Dutch mathematician and ‘father of modern philosophy’. Harriot is credited with introducing the less-than (<) and greater-than (>) inequality symbols. He was among the first to adopt the plus (+), minus (−) and equal (=) signs; to use lowercase letters for variables; and to prefer in his equations to bring all the terms over to one side, and equate that expression to zero.
* Hungarian astronomer Baron Franz Xaver von Zach (1754–1832). Von Zach, who spent 1783-86 in England as a tutor employed by the Saxon ambassador, Hans Moritz von Brühl, later became editor of a number of distinguished scientific journals.
* George O’Brien Wyndham, 3rd Earl of Egremont (1751-1837), an art lover, canal builder and commercial investor who was also keen on scientific innovation.
* The Earl of Egremont’s seat at Petworth in West Sussex. The current house was built in 1688 and remodelled in the 1870s, and stands on the site of a fortified manor house built by Henry de Percy, 1st Baron Percy (1273–1314), of which only the undercroft remains.
* Friedrich Bessel (1784–1846), a mathematician and astronomer from Westphalia in Prussia. Thomas Harriot and Nathaniel Torporley had made observations of a comet in 1607, which in 1705 astronomer Edmond Halley realised was in fact a recurring phenomenon seen in 1456, 1531, 1607 and again in 1682, known today as Halley’s Comet. Bessel used Harriot’s notes to refine Halley’s orbital calculations.