THE STKUCTURE OF THE NUCLEUS. 



27 



observations in such a way that corresponding coi'onas full on the same line. This 

 is here but partial!}' successful, probably because the importance of the time losses 

 is underestimated. The feature of the table is the prevalence of blues, and the 

 I'esults differ in this respect from those for the larger gh)bes below. 



The color abbi'eviations used easily suggest themselves, except in the cases of 

 gr green, bl blue, ol olive, cr ciiinson, op o[)aque oi' black, dk dark. Gray and black 

 will be wi'itten in full. I have thought it expedient to give a very complete series 

 of color observation, both because it is not clear that the sequences for large and 

 small globes are the same, and because of the difficulty of identifying different series. 



8. Observations with a larger globe. — The following table contains examples of 

 results chosen at random, for the larger globe 30 cm. in diameter, for difl'erent dis- 

 tances of the light, different exhaustions, and nucleations. These coronas ai-e easily 

 I'ecognized by aid of table 4, but their full classification is again difficult because 

 the time losses are not adequately allowed for. The coronal colors ai-e given from 

 within outward, and the number of exhaustions made is attached. In the first 

 part of the table the exhaustion is smaller than in the second. When compared 



TABLE 2.— PRELIMINARY DATA FOR CORONAL COLORS. LARGER GLOBE, DI- 

 AMETER 30 cm. EXHAUSTION, 76-58 cm. DISTANCE OF SOURCE, 



100 cm. OR LESS. 



' A second experiment required 13 exhaustions before coronas appeared. Sequences of color, similar. 



Exhaustions 76-53 cm. 



Fog reddish 

 Wh, bl-gr, rd 

 Yl-gr, rd, slate 

 Yl, rd, gr 

 Wh-yl, cr,gr,'pk 

 Wh-gr, gr-bl, rd 

 Yl, br, gr, pk 

 Wh,br,bl,rd, gr 

 Wh, cr, bl, gr, rd 

 Wh,rd,br,bl,gr,rd 



Wh, tawny 

 Wh, olive, br-rd 

 Yl-gr, viol 

 Wh, or-br, gr 

 Wh, cr, ol, rd, bl 

 Wh, gr, cr 

 Wh,or-rd,gr,viol 



1-2 

 3 



4 



5 



Gray, tawny ' 

 Wh,olive,rd,br 

 Yl-gr, slate 

 Wh, or-rd, gr 



' Blue later. Retrograde passage after exhaustion very marked. ^ Flame colors respectively, bl, bl, yl-br, pk. 



