Total Solar Eclipse of 1900 (May 28). :jG7 



S.E. N.E. N.W. S.W. 



Hoi-. 30 Hor. 30 Hor. 30 Hor. 30 



106 74 168 178 170 U 121 114 136 Leisurely. 

 104 74 164 176 164 122 116 135 Bating. 



The following readings show that in a leisurely setting the observa- 

 tion of extinction of the bands is satisfactory. 



1900. May 24. Ten settings for extinction of bands in the middle 

 of the field 16, 15, 16, 12, 16, 17, 16, 17, 17, 16. Mean 15 8 -8. 

 It is thus clear that the " racing " settings give results of about the 

 same order of accuracy as the leisurely ones. 



In the eclipse itself, the observations were made on the balcony of 

 the equatorial coude, and unfortunately, on account of other noises, 

 the signal, " Stand by," announcing that the beginning of totality was 

 approaching, was not heard by Mrs. Newall, who was standing in the 

 doorway of the balcony with a view of protecting her eyes from the 

 sunlight till the last moment. Nearly half of the duration of totality 

 had passed before she came into the open, and heard the twenty-eighth 

 beat of the metronome being called. Going at once to the polariscopes 

 she began to adjust them; she had set four of them " to extinction," 

 and had nearly completed the setting of the fifth, when sunlight 

 reappeared. With regard to the last observation, Mrs. Newall noted 

 an interesting point. She had nearly completed the setting to extinc- 

 tion when the bands suddenly became bright again, with black centre, 

 and she turned the polariscope counter-clockwise, from somewhere 

 near the reading 20, and had nearly set again to extinction before 

 realising that totality was over. The reading of the polariscope was 

 then found to be 345. 



The actual circle readings recorded immediately after the eclipse 

 were as follows, and it was noted that the bands were very faint : 



S.E. N.E. N.W. S.W. 



Hor. 30. Hor. 30. Hor. 30 



105-0 94-l 324-8 340 ?20 



[345 after return of sunlight.] 



These require small corrections for the index errors, which can only 

 be determined after the instruments return from Algiers, but it may 

 be provisionally stated that the angles made by the plane of polarisa- 

 tion with the vertical, read from the vertex clockwise, are as 

 follows : 



S.E. N.E. N.W. W. 



Hor. 30. Hor. 30. Hor. 30. Over corona. 

 60 49 280 295 ?305 356 



[From my own 

 observations.] 



