S8 CONTENTS OF THE CATALOGUE. 



Page 



Defects of focal Distance 315 



[m perfection of Focus 315 



Squinting 315 



Confusion of Colours 315 



Debility of Sight 316 



Cataract 3l6 



Employment for the Blind 316 



Production of Colours in Double Lights, 316 



Nature of Li»ht and Causes of Colours 3 18 



idistory of Optics 323 



|Dates 323 



Physics 324 



Astronomy 324 



Fixed Stars in General 325 



Stars visible in London 327 



System of Stars, Nebulae, and Double Stars 328 



Distance and Magnitude of the Slais 329 



Proper Motion of the Stars 330 



Changeable Stars and new Stars - 330 



Twinkling of the Stars 33 1 



Sun 331 



[Solar Atmosphere, or Zodiacal Light 332 



Planets in General 332 



Particular Planets 333 



Mercury 333 



Venus 333 



The Earth, in its Relations to the Celestial Bodies 333 



Vlai-s 334 



Juno , 334 



Pallas 334 



Ceres - 534 



Jupiter 335 



Saturn 335 



Georgian Planet S35 



Secondary Planets 335 



Supposed Satellite of Venus 335 



Moon j 335 



Satellites of Jupiter i 337 



Satellites of Saturn 337 



Satelliies of the Georgian Planet 337 



Comets 337 



Laws of Gravity in General 338 



Equilibrium and Figure of Gravitating Bodies 339 



Orbits of the Primary Planets 339 



Orbits of the Secondary Planets 340 



Orbits of Comets 34 1 



Projectiles from the Moon 341 



Rotation of the Earth and Planets 341 



Theory of the Tides 343 



Celestial Appearances in General, with Reference to the Earth '344 



Appearances of the Stars 344 



Appearances of the Sun 344 



