xxv.] THE COEONA. 365 



it as giving us a continuous spectrum such as is given by a solid 

 body, say the limelight, or the carbon pole in an electric lamp. 

 Associated with the continuous spectrum were certain bright 

 lines, so that astronomers were justified in regarding it as built 

 up of solid or liquid particles floating in certain gases per- 

 manent at the temperature of the solar atmosphere. 



This exactly fitted the old view, which supposed that all the 

 vapours which produce the Fraunhofer lines existed close to the 

 photosphere, and that there alone was there sufficient tempera- 

 ture to give us a line spectrum. 



It was natural, therefore, that after the eclipse of 1870, during 

 which it was supposed at the time, by myself among others, 

 that such a rich harvest of facts had been obtained confirming 

 the old view, that the detection of light reflected by these solid 

 or liquid particles was attempted. That this power of reflection 

 existed was found by Janssen in 1871, who saw the D line 

 dark in the spectrum of the corona. 



When I was first driven to the views I now hold, it became 

 obvious that if these statements regarding the corona were 

 strictly accurate my hypothesis was worthless. 



I was not able to make any crucial observations during 

 the eclipse of 1878 observed in the Rocky Mountains, for the 

 reason that my instrumental equipment was of the lightest. 

 But in 1882, when I had the opportunity of pursuing this 

 inquiry, the result at which I and others arrived was of no 

 uncertain sound. The spectrum of the corona as I saw it in 

 Egypt was of the most complex nature. It was distinctly not 

 a continuous spectrum resembling that given by the limelight. 

 Instead of the gradual smooth toning seen, say in the spectrum 

 of the limelight, there were maxima and minima producing an 

 appearance of ribbed structure, the lines of hydrogen and 1474 

 being, of course, over all. Of other bright lines distinct at any 

 great distance from the photosphere I saw none, nor any very 

 marked absorption lines, not even D or b, but I should add that I 



