AMERICAN 
JOURNAL OF SCIENCE AND ARTS. 
[THIRD SERIES] 
Art. LIX.—The Solar Atmosphere, an introduction to an account 
of researches made at the Allegheny Observatory; by S P. 
Laney, Director of the Observatory.* 
Ir has long been observed that the sun is not everywhere 
equally bright, but that the edge is darker than the center, and 
Since a self-luminous sphere should appear of sensibly uniform 
brilliancy, so as to present to the eye the appearance of a flat 
dise, this diminution of light must be due to some medium 
- se biog as at present. Though this value is erroneous, being 
deduced from imperfect data by processes which rest on a false 
i pothesis, it may yet serve to call attention to the importance 
ce. 
Am. Jour. So1.—Tamp ane ee X, No. 60*.—Dzc., 1875. 
