IV GENERAL SUMMARY 



formative activities in the organic and animated bodies? What has 

 been discovered does not by a long way exhaust the discoverable. 

 The imperfect! bility of empiric investigation makes the problem of ex- 

 plaining the changeability of matter from the forces of matter an indef- 

 inite one. 



A. URANOLOGICAL PORTION of the Physical Description of the Uni- 

 verse p. 26-28. 



Two sections, one of which comprises the heaven of fixed 

 stars ; the other, our solar system p. 26. 



. ASTBOGNOS Y ; Heaven of the fixed stars. 



I. The realms of space, and conjectures regarding that which 

 appears to occupy the space intervening between the heaven- 

 ly bodies p. 29-41. 



II. Natural and telescopic vision p. 49^-72 ; Scintillation of the 

 stars 73-83; Velocity of light p. 84-88; Results of photom- 

 etry p. 89-102. Order of the fixed stars according to their 

 luminous intensity. 



III. Number, distribution, and color of the fixed stars p. 103 

 139 ; Stellar clusters (stellar swarms} p. 140-143; The Milky 

 Way interspersed with a. few nebulous spots p. 144-151. 



IV. New stars, and stars that have vanished p. 151-160; Va- 

 riable stars, whose recurring periods have been determined 

 p. 160-177; Variations in the intensity of the light of staro 

 whose periodicity is as yet uninvestigated p. 177-182". 



V. Proper motion of the fixed stars p. 182-185; Problematical 

 existence of dark cosmical bodies p. 185-187; Parallax 

 measured distances of some of the fixed stars- p. 187-194; 

 Doubts as to the assumption of a central body for the whole 

 sidereal heavens p. 195-199. 



VI. Multiple, or double stars Their number and reciprocal dis * 

 tances. Period of revolution of two stars round a common 

 center of gravity p. 199-213. 



VII. Nebulous spots. Are these only remote and very dense 

 clusters of stars? The two Magellanic Clouds, in whicb 

 crowded nebulous spots are interspersed with numerous stel- 

 lar swarms. The so-called black spots (Coal-sacks) of the 

 Southern hemisphere p. 13-53 



/?. SOLAR REGION p. 53-134. 



I. The Sun considered as the central body p. 59-88. 



II. The Planets p. 88-134. 



A. General consideration of the planetary world 1 p. 88-1 34. 



a. Principal Planets p. 89-131. 



b. Secondary Planets p. 131-134. 



B. Special enumeration of the planets and their moons as parts 

 of the solar system p. 134. 



Sun p. 135-137. 



