SCIENTISTS OF THE NORTH-EAST OF SCOTLAND 119 
elected to it, and he remained there for six years until his appointment to 
a similar chair in Edinburgh University. But his tenure only lasted for 
one year. In October 1675, while showing the satellites of Jupiter 
through a telescope to some of his pupils, he was suddenly struck with 
blindness and died a few days afterwards at the early age of thirty-seven. 
Nowadays his name is chiefly remembered in connection with the series 
for expressing the inverse tangent of an angle in terms of the angle, a 
series which readily gives a value for. But his whole work on series and 
on quadrature of curves largely paved the way for Newton’s method of 
fluxions and, if for no other reason, he is justly entitled to a place among 
the hierarchy of mathematicians. 
In 1669 Gregory married Mary, the daughter of George Jamieson, the 
celebrated painter, the Vandyck of Scotland. His son, also James by 
name, held the Chair of Medicine in Aberdeen, and his son again was 
the famous Dr. John Gregory who helped to establish the fame of 
Edinburgh School of Medicine. But scientific ability was not confined 
to the family of the first James Gregory. His brother, David Gregory 
of Kinnairdy in Aberdeenshire, a successful merchant who commenced 
his commercial life in Holland, had the unique distinction of seeing three 
of his sons occupying Chairs of Mathematics in three British Universities. 
His eldest son David was born in Aberdeen in 1661 and was educated 
at Aberdeen and Edinburgh. It is said that he was led to the serious 
study of mathematics by carefully perusing his uncle’s papers which came 
into his hands. When only twenty-three years of age, he was appointed 
Professor of Mathematics at Edinburgh University, and he soon attracted 
the attention of scientists throughout the country by the ability and zeal 
which he showed in teaching the newly published Newtonian principles. 
When Dr. Bernard, the Savilian Professor of Astronomy at Oxford 
resigned, Gregory was appointed to succeed him, his candidature being 
strongly supported by Sir Isaac Newton and Flamsteed, the Astronomer 
Royal. In 1702 his Astronomiae Physicae et Geometricae Elementa was 
published. This is reckoned as his greatest work, and was esteemed by 
Newton as an excellent explanation and defence of his philosophy. In 
the prosecution of a scheme which was initiated by Bernard for preparing 
editions of the works of the great Greek mathematicians, Gregory under- 
took to do Euclid’s works, and in 1703 his Euclidis quae supersunt omnia 
appeared. Until the issue of Heiberg and Menge’s edition (1883-88) 
this was still the only complete edition of Euclid. Along with Halley, 
who was at that time his colleague as Professor of Geometry at Oxford, 
Gregory had begun to prepare an edition of Apollonius, but he had not 
gone far in this undertaking when he died in 1710, and Halley was left 
to complete the work. Of David Gregory’s other writings the most 
interesting is a small book on Practical Geometry, which was afterwards 
translated into English by Maclaurin and published in 1745. 
James, the second son of David Gregory of Kinnairdy, succeeded David 
in the Mathematical Chair in Edinburgh University, and Charles, the 
third son, was appointed Professor of Mathematics in St. Andrews in 
1707. He held the chair until 1739, when he was succeeded by his son, 
David Gregory, who lived until 1763. 
