OF CONTENTS. V 



Mercury p. 137, 138, 

 Venus p. 138-141. 

 Earth p. 141. 



Moon of the Earth p. 141-159. 

 Mars p. 159, 160. 

 The small planets p. 161 ; Flora, Victoria, Vesta, Ira, 



Metis, Hebe, Parthenope, Astraea, Egeria, Ireae, Euno- 



mia, Juuo, Ceres, Pallas, Hygeia ; 

 Jupiter p. 165-168. 



Satellites of Jupiter p. 169, 170. 

 Saturn p. 170-174, 



Satellites of Saturn p. 174, 175, 

 Uranus p. 175, 176. 



Satellites of Uranus p. 176, 177, 

 Neptune p. 177-180. 



Satellites of Neptune p. 180, 181. 



III. The comets p, 181-201, 



IV. Ring of the zodiacal light p. 201-204. 



V. Shooting stars, fire-balls, meteoric stones p. 204-5X26, 

 Conclusion p. 2S7-23Q. 



Corrections and additions to vol. iii,, p. xi., xii. 

 Index, p. 231-234. 



Special analysis of the individual sections of the astronomical part of 

 the Cosmos. 



C, ASTROGNOSY, 



I. Cosmical space: Only isolated portions are measurable p. 30. 

 Resisting medium, celestial atmosphere, cosmical ether p. 31, note t, 

 and p. 33, note *. Radiation of heat by the stars p. 35, note \. Tem- 

 perature of space p. 37-39. Limited transparency? p. 48. Regu- 

 larly decreased period of revolution of the Comet of Encke p. 39. 

 Limitation of the atmosphere 1 p. 40. 



II. Natural and telescopic vision : Very different sources of light pre- 

 sent similar relations of refraction p. 44. Different velocities of the 

 light of ignited solid bodies and that of frictional electricity p. 45. 

 Position of the Wollastonian lines p. 45. Influence of tubes p. 43. 

 Optical means^of distinguishing between direct and reflected light, and 

 the importance of the means to physical astronomy p. 45. Limits of 

 ordinary vision p. 48. Imperfection of the organ of vision ; false di- 

 ameter of the stars p. 52. Influence of the form of an object upon the 

 minimum visual angle in experiments as to visibility; necessity of a dif- 

 ference of luminous intensity of ^ l ff ; visibility of distant objects, posi- 

 tively and negatively p. 48-56. On the visibility of stars by day with 

 the naked eye from wells or upon lofty mountains p. 56. A feeble 

 light by the side of a stronger p. 49, note *. Extending ray and star 

 tails p. 52. On the visibility of the satellites of Jupiter by the naked 

 eye p. 50. Undulation of the stars p, 59. Commencement of tel- 

 escopic vision; application to measurement p. 60-62. Refractors of 

 great length p. 63. Reflectors p. 63. Day observations ; how strong 

 magnifying powers facilitate the finding of the stars by day p. 66. 



