156 HISTORY OF GEOLOGY AND PALEONTOLOGY. 



bodies took origin, and during condensation developed heat 

 and light. If a star has planets associated with it, as in the 

 case of our sun, the origin of these planets is, according to 

 Faye, to be traced to the original slow, whirling movement of 

 some part of universal matter. 



Considerable masses of primitive matter unite in the form 

 of flattened rings, originally surrounding an empty centre of 

 gravitation. The rings are gradually disrupted into a number 

 of rotating masses, whirling with the same direction as the 

 parent ring, greater masses attract smaller, absorb them, and 

 finally a spherical body is formed. The planets originate in 

 this way, those planets forming first whose component rings 

 are relatively nearer the centre of gravitation. Meantime, 

 finely divided fragments of matter meet in the centre of such a 

 system, and begin to give origin to a sun. It is impossible 

 here to enter further into these new conceptions of cosmogony 

 so recently advanced by Faye. 



The Sun. The first information about the physical constitu- 

 tion of the sun was obtained by the use of the telescope. 



David Fabricius, the son of a pastor in East Frisia, dis- 

 covered in the year 1610 movable spots on the sun, and his 

 observations were confirmed a few months later by the 

 Bavarian Jesuit Scheiner, by the Englishman Harriot, and 

 the Italian Galilei. Fabricius explained the sun-spots as 

 slaggy separations from the inner incandescent nucleus of the 

 sun; Scheiner regarded them as foreign masses circulating 

 round the sun ; Galilei thought them clouds occurring in the 

 sun's atmosphere. 



From the variability in the position of the sun-spots Scheiner 

 drew for the first time the important conclusion that the sun 

 rotated. 



The significance of the sun-spots is still a matter of dis- 

 cussion among astronomers. Herschel suggested in the early 

 years of last century that the sun-spots were cavities in the 

 glowing atmosphere, through which the dark body of the 

 sun was visible. This suggestion found much acceptance, 

 until it was disproved by the spectroscopical researches of 

 Kirchhoff. 



Kirchhoff in 1861 showed that the white-hot sun's mass was 

 surrounded by a photosphere in which numerous substances 

 familiar to us in the earth's constitution were present in a 



