C O N TEN T 8.

'-The variable Eccentricity of the Orbits

34 r, 342

' The Inclination thereof 343 ? &c.

theory of the Lunar Motions and Irregula-rities, 350

Motion of the Earths Axis explained ,, 351, &c.The Recession of the Equinoxes, 3 55

Method of computing the Quantity of Matter,Density and Weigh to/ Bodies , in the Sun,Earth, Jupiter, and Saturn, 356, &c.

APPENDIX II.

IjMPROVEMENT-S in OPTICAL INSTRU-MENTS.

/~\F the Universal Microscope, 363—365

Of the new Solar Microscope, 369-—372Of the new Reflecting Telescope, 366—369The Theory of ww Micrometer, 372—384Of the Improvement of Refracting Micro-scope^ and Telescopes by a Compos tion ofGlasses , 383—391

The latter Improvements of Refracting andReflecting Telescopes, 391*— 394

The Nature of Visual Glasses explained , andsewn to be an Improvement of Spectacles,

394