Lot 938: GREGORY, DAVID.

Praelectiones de motu in partes tres divisae... anno Domini 1685 (Institutiones astronomicarum partes tres... 1686; Lectiones opticae). [England, c. 1730]

Condition Note:

folio (306 x 188mm.), manuscript on paper, 404 numbered pages in a single neat scribal hand, the text written within two red-ruled margins, 29 lines to a page with catchwords, illustration: copious pen-and-ink diagrams both in the body of the text and on 19 folding 'plates', all keyed into text with relevant numbers (1-19 Motion; 1-15 Astronomy; 1-62 Optics), binding : early eighteenth-century blind panelled reversed calf, marbled endpapers, binding a trifle worn

DSB V, p. 522

The text of the 'Institutio astronomica' begins on p. 271 and ends on p. 320 (chapter 4 deals with the measuring of time, and chapter five with astrology). The 'Lectiones opticae' begin on p. 323.

Gregory's lectures on motion, astronomy (including a review of the Copernican system), and optics given at Edinburgh between 1684 and 1687, which cover all aspects of these subjects as understood and viewed at the time, are set out in the form of propositions, theorems and scholia (much like Euclid and the form used by Newton for Principia). They were never printed but were used by Maclaurin in his 1745 Treatise of practical geometry. This copy of Gregory's text must have been made for William Jones and probably dates from around 1730. There is other material to do with Gregory in the Macclesfield papers now in Cambridge, and there are manuscripts in the university libraries of both Edinburgh and Aberdeen. Gregory was a huge admirer of Newton, to whom in 1684 he had sent his Exercitatio geometrica, and he recorded many conversations and discussions with him. Newton recommended him for the Savilian chair of astronomy at Oxford. In his Astronomiae physicae et geometricae elementa of 1702 he printed Newton's classical scholia and his Theory of the moon's motions but without Newton's name.