ASTRONOMY. 15 



from 0.3" or 0.4" to 3" or 4". Their forms are generally cir- 

 cles or ellipses, but these forms are sometimes greatly al- 

 tered. This granulation is apparently spread equally all 

 over the disk. The brilliancy of these points is very varia- 

 ble, and they appear to be situated at different depths be- 

 low the photosphere : the most luminous particles, those to 

 which the solar light is chiefly due, occupy only a small frac- 

 tion of the solar surface." The most remarkable feature, 

 however, is "the reticulated arrangement of the parts of the 

 photosphere." "The photograms show that the constitution 

 of the photosphere is not uniform throughout, but that it is 

 divided in a series of figures more or less distant from each 

 other, and having each a special constitution. These figures 

 have, in general, rounded contours, but these are often al- 

 most rectilinear, thus forming polygons. The dimensions of 

 these figures are very variable ; some are even 1' in diameter 

 (over 25,000 miles)." " Between these figures the grains are 

 sharply defined, but in their interior they are almost effaced, 

 and run together as if by some force." These phenomena 

 can be best understood by a reference to the figures of M. 



Janssen. 



SOLAE ECLIPSES. 



The best general account of the principal results of the to- 

 tal eclipse of July 29, 1878, which has yet appeared, was 

 written by Professor C. A. Young in the New York Times of 

 August 1G. A portion of this is given below : 



"As regards the physics of the sun and the corona, the 

 principal and most important result of all the observations 

 bearing upon this subject is to demonstrate a decided sym- 

 pathy and connection between the condition of the sun's vis- 

 ible surface, as indicated by the number and character of the 

 sun's spots, and the constitution of the corona. 



"At the present time the sun's spots are at their mini- 

 mum; whole months have passed without the appearance of 

 a single one. The chromosphere, or colored envelope of hy- 

 drogen and other gases which immediately surrounds the 

 sun, has also been correspondently quiescent, and the so- 

 called 'prominences' have been few and small. Of course, 

 it was a question of interest whether the corona also would 

 show a corresponding difference of condition from that indi- 

 cated in 1869 and the later eclipses, when the sun's surface 



