42 ANNUAL EECORD OF SCIENCE AND INDUSTRY. 



mosphere in the winter time is much less favorable to ac- 

 curate observations than in the summer time. Vierteljahrs- 

 schrift der Ast^'onom. Gesellschaft. 



THE CONSTITUTIOIS' OF THE SUN. 



The discussion as to the nature of the solar spots that has 

 now for over a year occupied the attention of the Frencli 

 Academy of Sciences seems to have consisted chiefly of a 

 series of hypotheses, proposed by Secchi, Vicaire, and others, 

 in opposition to the well-established views of Faye. The 

 latter has, with some success, defended his own views, and 

 shows the weak points or fallacies in the reasoning of other 

 astronomers on this subject. In one of the last communica- 

 tions which we have from Faye, he gives an excellent resume 

 of the various hypotheses that have from time to time been 

 proposed to account for the phenomena seen upon the sun's 

 surface. He states as follows : 



1. They tell us that the sun is a body dark and cold, sur- 

 rounded by a thin shell of gas, or of certain physical forces 

 developing incessantly light and heat. Gaseous eruptions 

 rise from the solid nucleus and form the sjjots. This hy- 

 pothesis has obtained very generally until the last few years, 

 although it seems to be a case of perpetual motion. 



2. Others aflirm that the sun is an incandescent liquid 

 globe, upon which appear scorioe like those to be seen in 

 fused metal. It would be difficult to say how any such globe 

 is kept free from being incrusted. 



3. Others believe that the sun is a gaseous mass, kept at a 

 temperature of many millions of degrees, and agitated by 

 eruptions more or less volcanic. According to Tacchini, the 

 spots are due directly to these eruptions. According to 

 Secchi, they are due indirectly to depressions. What kind 

 of eruptions can these be arising from the interior of a gas- 

 eous mass ? 



4. Others pretend that, except the temperature, the sun is 

 like the earth ; that at least it has an atmosphere like ours, 

 the winds blow as ours do, and the tempests even, and es- 

 pecially the clouds are like ours. 



5. Others affirm that the sun has the sensibility and the 

 impressibility of explosive matter to such an extent that the 

 most delicate forces, such as the attraction of the planets 



