W. Huggins— Photographing the Solar Corona. 129 
Tays admitting in the best plates of measurement and drawin 
om them. This agreement in plates taken on different days 
I 
the sun but the corona also is photographically reversed, and 
in these plates, having the appearance of a positive, the white 
respond in form and general orientation, and the inner corona, 
which is more uniform in height and definite in outline, is also 
very similar in my plates to its appearance in those taken dur- 
ing the eclipse, 
sures of the average height of the outer and of the in- 
her corona in relation to the diameter of the sun's image are 
