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 imperfectibility 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. 



a. Astrognosy ; Heaven of the fixed stars. 



I. The realms of space, and conjectivres 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 afeto 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 stars 

 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 which 

 crowded nebulous spots are interspersed with numerous stel- 

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

 Southern hemisphere — p. 13-53 



0. 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 — p. 88-134. 



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. 



