Scientific Intdligence. 

 III. ASTKONOMT. 



lipse trom JSature^ the excellent scientitc weekly i 



al direction of the astronomer, Mr. Lockyer, and published 



t scientific weekly under 



eaitonai direction oi the astronomer, Mr. JLockyer, and pi 

 by MacMiUan & Co. London, and 63 Bleecker St., New Y 



Mediterranean Eclipse, 1870; by J. Norman Lockyer.— Cloud 

 in Sicily, cloud in Spain, cloud in Africa. Such at first sight might 

 seem to be the only result of all the observations made on the 

 eclipsed sun of 1870. 



But, after all, has the oracle been silent ? I think not. Dare 

 we, however, say that the great problem of the Corona, that one 

 among the many still outstanding difficulties which the eclipse 

 was invoked to settle, is settled ? This, perhaps, would be saying 

 too much, but still, I think, a step in advance has been made. The 

 oracle has spoken darkly, perhaps, but it has spoken. 



Let me endeavor to put the question as it stood a few weeks ago 

 as briefly as possible. 



Beginning the story some few years back we find the corona, a 

 halo of white light around the moon, with a height sometimes rep- 

 resented as equal to the moon's diameter, sometimes more, some 

 times less, with a border d discretion,— so much did the drawing> 

 vary— regarded as the solar atmosphere. 



Some thought the red prominences to be mountains, other ob- 

 servers called them clouds. . . 



The polariscope was brought up with a view of detemiining 

 whether the corona shone by reflected light or not. The result of 

 this new method of observation was doubtful. 



In the Indian eclipse of 1868 M. Janssen, by means of the spec- 

 troscope, still another aid, determined that the prominences were 

 masses of hydrogen gas, but there was no final word about the 

 corona. Major Tennant observed that its spectrum was contuiuous. 

 Later in the same year Dr. Frankland and myself approximateiv 

 determined the pressure of the prominence gases by means of a ne 

 method and laboratory experiments, and at once stated ourconvu- 

 tion that the extensive corona, which had been depicted and rep- 

 resented by Kirchhofi" and others to be the solar atmosphere, m^ 

 be something else. This was our idea. I cannot quote our.^/'^*;'' 

 for I am writing in Venice and have no copies of our paper with m • 

 _ In the American eclipse of 1869 the problem was advanced c 

 siderably, perhaps even more considerably than we can yet toroj 

 an Idea of, writing as we must still do doubtfully. I do not J^ 

 to the drawings, for they varied considerably, but to the oX>m 

 tion that the light of the outer corona, like that of the prommen^e^ 

 gave a bnght-line spectrum. But as at least some of the ooser 

 gave positions doubtfully, "near C" and "near E," I thought tna^ 

 the explanation was still possible which regarded the corona a. ^ 

 terrestrial origin ; that is, which assumed it to be an appearance 

 to the presence of light in our own atmosphere. The proWem 

 one of such difiiculty that there seemed a possibility that, t'T^, ^j 

 unexplained cause, some of the solar light might be difliised ana 



