182 Mr. J. X. Lockyer on the recent Eclipse of the Sun [Jan. 27, 



edge of the field, disappeared. Thus it was evident that this line* be- 

 longed not to the spectrum of the protuberance, but to that of the corona. 

 Mv impression, but I do not feel at all sure of it, is that the two faint 

 lines between it and D 3 behaved in the same manner, and are also corona 

 linesf. 



" I am confirmed in this opinion by Professor Pickering's observation. 

 He used a single-prism spectroscope, with the slit of the collimator simply 

 directed to the sun, and having no lens in front of it. TVith this arrange- 

 ment he saw only three or four bright lines, the brightest near E (1474). 

 Now this is exactly what ought to occur if that line really belongs to the 

 corona, which, from its great extent, furnished to his instrument a far 

 greater quantity of light than the prominences. 



" By this time the moon had advanced so far that it became necessary to 

 shift the slit to the great prominence on the opposite side of the sun. 

 While my assistant was doing this, I suppose I must, in the excitement of 

 the moment, have run my eye-piece over the region of the magnesium lines 

 (b), and thrown them out of the field before he had brought anything upon 

 the slit. At any rate I saw nothing of these lines, which were evident 

 enough to several other observers, and can think of no other way to account 

 for their having escaped me. The F line in the spectrum of the great 

 protuberance was absolutely glorious, broad at the base and tapering 

 upwards, crookedly as Lockver has before ofteu observed. Next appeared 

 a new line, about as bright as 1474 at 2602 = 2 of KirchhofFs scale. Its 

 position was carefully determined by micrometrical reference to the next 

 line, 2796 K (hydrogen y), which was very bright ; h was also seen, very 

 clear, but hardly brilliant. In all I saw nine bright lines. 



* ■ On two or three occasion? previously I had been very much surprised at not being 

 able to detect this line in the spectrum of unusually bright prominences. On the other 

 har.d. I once found it very easy to see at a place on the sun's limb where the other 

 chromosphere lines, usually far more brilliant, were almost invisible.'' 



t " A careful examination of the photographs, especially 2s o. 2 of the Burlington 

 totality pictures, somewhat diminishes my confidence in the conclusion of the text as to 

 the nature of these three lines 1 1250, 1350. and 1474 ). They certainly do not belong 

 to the spectrum of the most brilliant portion of the prominences ; but around the pro- 

 minences of the eastern limb, on which the slit of the spectroscope was directed during 

 the first half of the totality, the photograph shows a pretty extensive and well-defined 

 nebulosity, evidently distinct from, though associated with, the brilliant nuclei. iNow 

 it is possible that these lines may belong to this nebulosity, and not to the corona 

 proper : for I cannot recall with certainty whether 1474 retained its brilliance at any 

 considerable distance from the prominences, or only in their immediate neighbourhood. 

 My strong impression, however, is that the former was the case, and that the text is 

 correct. I may as well confess that my uncertain memory here is due to the fact that 

 just at this time, while my assistant was handing me the lantern with which to read the 

 micrometer-head. I looked over my shoulder for an instant, and beheld the most beau- 

 tiful and impressive spectacle upon which my eyes have ever rested. It could not have 

 been for five seconds ; but the effect was so overwhelming as to drive away all certain 

 recollection of what I have just seen. "What I have recorded I recall from my notes 

 taken down by my assistant." 



