James Gregory
(1638-1675)

The Scottish mathematician, invented the first reflecting telescope in 1663. He published a description of the reflecting telescope in "Optica Promota," which was published in 1663. He never actually made the telescope, which was to have used a parabolic and an ellipsoidal mirror. The Aberdeen mathematician, is arguably the greatest scientist associated with St Andrews. In 1661, at the age of 23, he invented a type of reflecting telescope, later to be described as `Gregorian'. He was appointed to the newly established Chair of Mathematics at St Andrews in 1668 and almost immediately began to plan an observatory. In 1673 he was authorised by the University to go to London specifically to purchase `. . . such instruments and utensils as he with advice of other skilful persons shall judge most necessary and useful.' His purchases included three clocks, made by the leading London clock maker, Joseph Knibb - a matched pair of long-case clocks and a smaller split-second timepiece (the first such instrument ever produced), which are still in the possession of the University. Gregory described these clocks in a letter dated 19th July, 1673 from Gregory to John Flamsteed, the first Astronomer Royal at Greenwich. Another letter of 1674 mentions that other instruments were acquired, and these may well have included the great planispheric astrolabe and armillary sphere made by the Elizabethian engraver Humphery Cole, and the mariner's astrolabe of Elias Allen. Support for the connection between Gregory and the Elizabethian instruments is provided by the fact that the great planispheric astrolabe has a plate which was produced specially for it by John Marke, a London instrument maker of Gregory's period, which enables the astrolabe to be used at a Scottish latitude.

Gregory was a friend of John Collins, a leading London mathematician, who had studied at Cambridge and kept him abreast of recent discoveries. Gregory may possibly have visited Isaac Newton at Cambridge, as the more famous mathematician frequently relied upon Gregory's work in subsequent years. Indeed the pair were often working on very similar projects at almost identical times. In 1667, for example, Gregory developed converging series to obtain quadratures, a process later used by Newton, who remarked: "The same year I found the methods of tangents of Gregory. . . and in November had the direct method of fluxions!"

However, after initial enthusiasm, the St Andrews academics found Gregory's `New Philosophy' distasteful: `a prejudice which the Masters of the University did take at Mathematics' (Gregory's own words) led to violence as students were forcibly kept from his lectures. In 1674 Gregory accepted an invitation to become a professor at Edinburgh University, but died the following year, aged, 37. A member of an incredibly illustrious scientific family, Gregory's contribution to the field of mathematics and natural philosophy was immense. Indeed he is unlikely to be forgotten, as telescopes made to his design will forever carry his name.

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