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Numb. 53.
PHILOSOPHICAL
TRANSACTIONS.
November 15. 1669.
The Contents.
A Description of Dr. Christopher Wren's Engin, designed for Grinding Hyperbolical Glases. Some Inquiries concerning the Salt-springs at Nantwich, answered. An Extract of a Letter, concerning the Death of the Bigg-breasted Woman, discoursed of in Numb. 52.An accompt of some Books: I. CERTAIN PHILOSOPHICAL ESSAYES, and other TRACTS by the Honorable ROBERT BOYLE: The Second edition, enlarged. London; printed for H. Herringman in the New-Exchange; A. 1669.II.DEL MOVIMENTO DELLA COMETA, apparsa A. 1664: Da PIETRO MARIA MUTOLI in Pisa, in 4°.III.ERASMI BARTHOLINI de COMETIS A. 1664. & A. 1665. Opusculum. Hafniæ in 4°.IV.SYLVA & POMONA, reprinted with Enlargements, by I. EUELYN. Esquire &c.
A Description
of Dr. Christopher Wren's Engin, designed for grinding Hyperbolical Glasses; as it was in a manner promised Numb. 48. p. 962..
We shall give it in the Authors owne words, as followeth.
SInt tria Corpora terendo idonea, P. Q. R; quorum P. & Q. sint æqualia & Columnari forma, R verso Corpus Lenti-forinc. P. rotetur circa axin A B; Q, circa C D; & R, circa E G.Sint
