HE Right Honourable the Earl of Pem broke. Mr. Samuel Pachel M. A. Rev. Mr. Parne. Fellow of Trinity College and Librarian of the Univerfity of Cambridge Books. 4 Rev. Caleb Parnham S. T. B. Fellow of Saint Rev. Mr. Pate of Cajus College Cambridge. Mr. Simon Patrick Fellow of Cath. Hall Camb. Mr. Henry Pennant of Queen's College Camb. Mr. Joshua Platts of Leicester. Mr Charles Plucknet of Sidney College Camb. And. Plummer M. D. Prof. of Med. at Edinb. Henry Plumtree M. D. Mr. Charles Plumtree Fell. of Qu. Coll. Cambr. Mr. William Potter of Gainsbrough. John Pringle M. D. Rev. Mr. Prior late Fell. of Tria. Coll. Camb. John Pulland Efq; Samuel Pye M. D. Q. Queens College Library Cambridge. Riccards. R. Rev. Mr. Morgan Fell. of Trin. Coll. 6 Books. MR. Robarts Efq; 6 Books. Mr. Morgan late Anatomy Profeffor at Camb. Mr. Corbyn Morris. Rev. Mr. Mofs Fellow of Cajus Coll. Camb. Mr. Alex. Munroo Prof. Anat. at Edinburgh. Rev. Mr. William Murdin S. T. B. Rev. Mr. Murgatroyd. N. IS Grace the Duke of Norfolk. H Mr. Nailer. Dr. Nettleton of Halifax. Rev Mr. Peter Newcome of Queens Coll. Camb. Roger North Efq; Honourable Mr. North. Bryan Robinson M D. Matthew Robinfon Efq; Rev. Jonathan Rogers D. D. Senior Fellow of Trinity College Dublin. Rev. George Henry Rook M. A. Fellow of Chrift College Cambridge. Patrick Rofs of Innernethy Efq; Charles Roffe Eiq; *William Roffe Elq; Rev. John Rowning M.A. William Rutty M. D. late Sec. to the R. Society. John Ruffel Efq; Dudley Ryder Efq; his Majefty's Attorney Gen. Thomas Whichcot Efq; of Harpfwell.. Rev. Mr. Whitehall Fellow of Trinity College Mr. John Whitfield Surgeon at Salop. Rev. Dr. Wilcox Mafter of Clare-Hall Camb.. *Mr. Francis Wilks. Rev. Mr. Williams Rector of Ockham. Rev. Mr. Benjamin Wilson Prebendary of York *Clifton Wintringham M. D. Clifton Wintringham Jun. M. D. *Rev. Mr Witton. Francis Wollafton Efq; Thomas Woodford Elq; George Wright Elq; Mr. Robert Wright of Winnick. Rev. Mr. Henry Wrigley Fellow of Saint Johns Cambridge. Peter Wyche Efq; . A TABLE CHAP. 6. Concerning the Origine and Caufe of Colours. 70% CHAP. 7. Concerning the caufe of Refraction, Reflection, Inflection and 86 CHAP. 8. Concerning Transparency, Opacity and Colours in Bodies. 95 CHAP. I. CHAP. 5. BOOK II. A Mathematical Treatife. To find the Focus of Rays reflected from any given Surface. 100 To determine the place, magnitude and fituation of Images formed by reflected Rays. 103. 104. To find the Focus of Rays falling almoft perpendicularly upon To determine the apparent Distance, Magnitude, Situation, degree of Diftinctness and Brightness, the greatest Angle of Vifion and Vifible Area of an Object, feen by rays fucceffively. reflected from any number of plane or spherical Surfaces; or fucceffively refracted through any number of Lens's of any. fort; or through any number of different Mediums, whofe Jurfaces are plane or spherical: with an Application to TeleJcopes and Microscopes. III. CHAP. 6. CHAP. 6. To determine the Aberrations of rays from the geometrical fo- 134 CHAP. 7. Arefracting or reflecting Telescope being given, whose aper- ture and eye-glafs are adjusted by experience, to determine the length, aperture and eye-glass of another telescope, thro' CHAP. 8. Contains general Properties of Focus's and Images, belonging to the Eye and to any number of Mediums: with general Con- ftructions fhewing the Variations of the apparent Distance of an Object, and of the real Distance of its last Image from the eye, caufed by a direct motion of the eye, object or mediums. 149 CHAP. 9. Determinations of Focus's of rays falling with any degrees of Obliquity upon any number of reflecting and refracting fur- CHAP. 12. To determine the apparent Shapes, Pofitions, Magnitudes and Diftances of large Objects, feen by rays that fall upon reflect- ing or refracting furfaces, not only perpendicularly or almost perpendicularly, but with any degrees of Obliquity. CHAP. 13. The Theory of the Aberrations of rays is refumed and carried farther, in order to discover the limits of perfection of re- flecting and refracting Microscopes; and to determine for A Mechanical Treatife. CHAP. I. Methods of grinding and polishing Glaffes for Telescopes; 281 CHAP. 2. Methods of cafting, grinding and polishing Metals for re- 301 |