118 Mr. G. M. Seabroke on the Determination whether 



4. What spectrum ought we to get from the corona after totality ? 



5. What spectrum ought we to get before totality on the fol- 

 lowing side of the moon ? 



6. What difference will there be between the spectrum of the 

 central portions of the corona and that of the distant parts during 

 totality ? 



With regard to 1. During the Indian eclipse, Major Tennant 

 writes : — " Directly I saw the whole moon in the finder I set the 

 cross-wires immediately outside its upper limb. By the time I 

 got to the spectroscope the cloudy range seen in the photographs 

 had vanished from the slit, and I saw a faint continuous spectrum. 

 Thinking that want of light prevented my seeing the bright lines 

 which I had fully expected to see in the lower strata of the co- 

 rona, I opened the jaws of the slit and repeatedly adjusted by the 

 finder, but without effect. What I saw was undoubtedly a conti- 

 nuous spectrum, and I saw no bright lines. There may have been 

 dark lines, of course ; but with so faint a spectrum and the jaws 

 of the slit wide apart they might escape notice." With respect 

 to the American eclipse, Professor Pickering, with an ordinary 

 chemical spectroscope directed to the sun's place during totality, 

 saw a continuous spectrum with two or three brright lines, one 

 "near E" and a second "near C" Professor Young, while ex- 

 amining a part of the prominence at + 146°, saw C, near D, a 

 line at 1250 + 20, and another at 1350 + 20, and the 1474 K 

 line very bright, but not equal to C and D 3 ; but he observed 

 that the 1474 K line, unlike C and D 3 , extended across the spec- 

 trum ; and on moving the slit away from the prominence it per- 

 sisted, while D 3 disappeared. He also believes that the two 

 faint lines between it and D 3 behaved in like manner. On ex- 

 amining a prominence on the other side of the sun, he observed 

 nine lines and a faint continuous spectrum without any traces of 

 dark lines in it. 



As to the second point, let us find what spectrum we ought 

 to obtain from a corona at a point on the earth where the limbs 



of the sun and moon are in line, — that is, where the eclipse is 

 total exactly. 



