THE ECLIPSE OF 1878. 135 



less in number, and had still more remarkably di- 

 minished in brightness and in the signs which they 

 afforded of eruptive solar action. The eclipse observers 

 saw only one prominence, resembling the i horn,' which 

 was the most remarkable feature of the eclipse of 1868. 

 "This single prominence was ' very dim ; ' indeed, the 

 observers in Colorado did not see it at all, for though 

 they mention two protuberances, they add that ' there 

 was an entire absence of the pinkish red flames 

 observed on some previous occasions ; ' whence we may 

 safely conclude that by protuberances they mean 

 masses of red matter not extending high above the 

 sierra. We thus find an explanation of the circum- 

 stance, which had been thought perplexing, that during 

 some eclipses very carefully observed before the actual 

 recognition of the red prominences no red flames were 

 noticed. We now see that during an eclipse observed 

 when the sun is without spots the prominences might 

 very easily escape recognition, at least by observers 

 not aware of the existence of such objects. 



But it was about the corona that astronomers chiefly 

 expected to obtain information during this eclipse, and 

 certainly the result has confirmed their anticipations. 

 First, it was discovered that the corona had changed 

 entirely in form, in size, and in the quality of its light, 

 if not in its physical constitution, since the eclipse of 

 1871. As observed on that occasion, it extended to a 

 distance of more than 1,000,000 miles from the sun. 

 As photographed, it showed an extension of at least 

 700,000 miles. It was exceedingly complicated in 



