GREGORY. 



help of an hyperbola, a converging ferii-s for making loga- 

 rithms, whicli is recommended by Dr. Halley for praftical 

 piirpofes : he fent to Mr. Collins the folution of the 

 famous Keplcrian problem by an infinite fcries : he dif- 

 covercd a method of drawing tangents to curves geo- 

 metrically, without any previous calculation, and many 

 other things whicli fliew that the niofl brilliant part of his 

 charafter was that of his mathematical genius as an inventor. 

 Eiog. Brit. 



Gregory, David, nephew of the preceding, an able 

 mathematician, was born at Aberdeen in the year 1661. 

 He was t!ie elded fan of Mr. David Gregory who had the 

 fingular fortune to fee three^flf his fons all profeffors of ma- 

 thematics, at tlie fame time, in three of the univerfities, i-iz. 

 David at Oxford, his fecond fon James at Edinburgh, and 

 his third foil Charles at St. Andrew's. David, the fubject of 

 this article, received the early part of liis education at his 

 native place, but completed his ftudies at Edinburgh, where 

 he took his degree of AM. and fo greatly did he diftin- 

 guifh liimfclf in fcientific piirfuits that he was eletled pro- 

 feflbr of mathematics in that univerfitv, when he was cmly in 

 his twenty-third year. About this period lie publidied from 

 his uncle's papers, witli confiderable additions of his own, 

 " Exercitatio Geometriea de Dimenlloue Frgurarum, five 

 Specimen Methodi generalis dimetiendi qiialvis Figuras." 

 He foon perceived the excellence of the Newtonian philo- 

 fophy, and was the lirll who iiad the merit of introducing 

 it into the Ichoolsby his Ictf ures at Edinburgh. In this city 

 he remained as mathematical profeffor with dillinguiilied ho- 

 nour and applaufe till the year 1691, when hearing of Dr. 

 Bernard's intention to refign the Savilian profelForfhip of 

 allronomy at Oxford, he went to London, and was intro- 

 duced to fir Ifaac Newton, who, conceiving highly of his 

 talents, recommended him to be chofen a fellow of the Royal 

 Society. Nev/ton introduced him to the notice of Mr. 

 Flamllead the ailronomer royal', and with their recommenda- 

 tions he was elected Savilian profeffor, though Mr. Halley 

 was a competitor. Their rivalfliip laid the foundation of a 



Ecrmanent friendlliip between thefe eminent men, and Hal- 

 ;y afterwards was the colleague of Gregory, by obtaining 

 the profefforlliip of geometry in the fame univerihy. In 

 1695- he publilhed thi fubilance of his optical lectures 

 which had been read at Edinburgh. This work was entitled 

 " Catoptrica; et Djcptrics Spherica; Elementa," 8vo. Dr. 

 Gregory, in 1697, gave a demonflration of the Catenarian 

 curve, or that curve which is formed by a chain failened at each 

 end. The paper on thw curve was inferted in the " Philo- 

 fophical Tranlaftions," and alfo in a work of much repu- 

 tation, entitled " Mifcellanea Curiofa," as one of the nobleft 

 difcoveries that had at that time been prefented to the Royal 

 Society. Tlie moll celebrated work of this learned pro- 

 feffor appeared in the year 1 701, entitled " AftronomiK 

 Phyfics ct Geometricas Elemeiita." This was written chiefly 

 witli t!ie defigii of explaining fir Ifaac Newton's geometry 

 of the centripetal forces, as far as his difcoveries in aflro- 

 nomy are built upon it, and to throw the agronomical part 

 ef his Priixipia into a new and more intcllicrible form. It 

 was afterwards, tranflated into Englifh, of which tht- fecond 

 fdition was publiihed in 1726, in two volumes oftavo, en 

 titled "The Elements of Phylical and Geometrical Allro- 

 nomy, &c." This imprefilon v/as revifed and correfttd by 

 Mr. Stone. In 170^, our author pubhilied a fplendid folio 

 edition of the works of Euclid in Greek and Latin. He now 

 began to prepare, in conjunction with Dr. Halley, a new 

 edition of " Apollonius's Conies," but he h.id not proceeded 

 very far in the undertaking before he was cut off by death in 

 1710, when only ia the forty-ninth year of his age. Bclides 



the works of Dr. Gregory printed in his lifetime, two others 

 were publitlied after his deceafe ; one " A Ihort Treatife ok 

 the Nature, &c. of Logarithms/' printed at the end of Dr. 

 Kcill's tranflation of Commandine's Euclid ; and the other 

 «'A Treatife of Praftical Geometry," publiflied by Mr. 

 Maelaurin in 1745. 



GuEGORY, Ja.me'?, brother of the preceding, rofe to high 

 eminence as a mathematician. He fucceeded his brother in 

 the profefforlhip of mathematics at Edinburgh, which oflicf^ 

 he held thirty-three years with great reputation, and retiriaj 

 in 1725, was fucceeded by the celebrated Maelaurin. 

 Charles, the other brother, was created profeffor of mathe- 

 matics at St. Andrew's, by queen Anne in 1 707. This 

 oflice he held with great credit thirty-two years, when he 

 reiigr.ed in favour of his fon David, who fucceeded him ia 

 1739. He died in 1763. He pubhraed a compendium o£ 

 arithmetic and algebra in I^atiu, entitled "Arithmcticx ct; 

 Algebrx Compendium, in Ufum Juventutis Academicae," 

 Edin. 1736. Biog. Brit. 



Gregory, Dr. George, was a native of Ireland, but 

 at the death of his father, who was a clergyman, and a very 

 elegant fcholar, the fubjecl of this article was brought to 

 l^iverpool, by his mother, who was a native of Lancadiire, 

 where he received the elements of a learned education, which 

 he completed at Edinburgh. He took orders in the chnrcK-- 

 in 1778, and was curate at Liverpool till the year 1782^ 

 when he removed to London, and obtained the curacy of 

 Cripplegate. In 1785 he became known as the author of 

 a volume of " Effays," which had an extenfrvc fale, and went: 

 through feveral editions ; and in 1789 he publifhed a tranila- 

 tion of Lowlh's leclures " On the Sacred Poetry of the 

 Hebrews," which was well received by the public. In I he 

 year 1804 he was prefentetf, through the intereil of lord 

 Sidmouth, by his maieilv, to the hving of Weftham, in 

 Effex ; he- had prcvioudy to this obtained marks of diftinc- 

 tion from the bifliop of London, which,, however, were 

 attended with very fraall portions of emolument. Dr. Gre- 

 gory did not live long to enjoy the cale and independency 

 which his noble friend intended, by the prefentation of the 

 living of Weftham; he died March 12, 1808. Befides, the 

 works already mentioned, he was author of a volume 

 of '« Semions," of the "Economy of Nature," in three 

 vols. ; of " Letters on Literature," in two vols ; and was- 

 likewife the editor and fuperintendant of an " Encyclopedia; 

 of Arts and Sciences," in two volumes 410. He was au- 

 thor of a Church Hiitory in two vols. 8vo. ; and of the life 

 of Chatterton, for whofe fate he felt the moll nncere com- 

 miferation, and divers other works with and without his 

 name. Monthly Magazine. 



Gregory, Joiix, an eminent phyfician, and profeffor of 

 the pradice of phyfic in the univcrljty of Edinburpli, was 

 born in May, 1725. His father was profeffor of medicine, 

 in King's college, Aberdeen ; and his grandfatlier was pro- 

 feffor of mathematics, iirll at St. Ajidrew's,.and niterv.-ards 

 at Edinburgh. Thus Dr. Gregory was the third profeffor 

 of his family in a lineal defcent : and it dei'erves to be re- 

 marked, that, from his great-grandfather, David Gregory, 

 efq. of Kinairdy, he was the fifteenth defcendant who had 

 held a profefiorlhip in a Britifh univerfity : his fon now iills. 

 the fame chair at Edinburgh. 



John Gregory began the iUidy of medicine at Aberdeen,, 

 and afterwards profeci.ced it at Edinburgh, Leyden, and 

 Paris. In the 20th year of his age, he was elected pro- 

 feffor of philofophy in King's college, Aberdeen, and had 

 at the fame time the degree of doftor of medicine conferred 

 upon him. In the year 1756, upon the death of his bro- 

 ther, Dr James Gregory, who had fucceeded his father as 

 2 proR'ffor 



