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 plane ts^p. 161 ; Flora, Victoria Vesta, Iris, 



Metis, Hebe, Parthenope, Astraea, Egeria, Irene, Euno 



mia, Juno, 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. 204-226 

 Conclusion— p. 227-230. 



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. 



a. AsTROGNOsy. 



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

 Resisting medium, celestial atmosphere, cosmical ether — p. 31, note I, 

 and p. 33, note *. Radiation of heat by the stars — p. 35, note %. Tern 

 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 ? — 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 -^^ ; visibility of distant objects, posi- 

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

 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 findin^j of the stars by day — p. 66 



