f 594 ) 



the bpectriim, secured at Yiziadrug (luring tlie 1898 eclipse^); the 

 sixth cohiuiu shows the absorbing substances. 



In a similar way Table II has been composed; here we ünd tiic 

 lines, which on the reproduction appeared to be strengthened 

 in the abnormal spectrum. 



The result is very strikmg. W e a k e n e d lines c o r r e s j) o n d 

 to chromosphere line s, almost w i t h o u t exception; 

 most f t h e strengthened lines, on the other h a n d, 

 are not to be f o u n d in the s p e c t r u m o f' the c h r o m o- 

 s p h e r e. 



LocKYER gives the strength of the chromosphere lines on a scale 

 such that 10 indicates the strongest and 1 the faintest lines. If we take 

 into account that in his list the greater part of tlie lines bear the 

 numbers 1 and 2, our table shows us, that by merely obser\ing the 

 abnormal solar spectrum we have been able to pick out s t r o n g 

 chromosphere lines. This cannot be chance. Undoubtedly botli phe- 

 nomena — the weakening of Frauidiofer lines in the abnormal spec- 

 trum and the origin of the chromos|)liere spectrum — are to be 

 explained in close relation with each other. 



The strengthening of lines in the abnormal spectrum does 

 not, on the contrary, seem to be so directly connected w itli the com- 

 position of the chromosphere spectrum. 



If our view be correct that the chromospheric light has been se- 

 parated by strong i-ay-curving from tlie "white" light emitted by 

 deeper layers, those special radiations must, as a rule, show reduced 

 intensity in the spectrum of the Sun's disk ^). Fraunhofer lines cor- 



1) LocKYER, Ghrisholm-Batten and Pedler. "Total Eclipse of the Sun, January 

 22, 1898. — Observations at Yiziadrug," Phil Trans., A, vol. I'JT, p. 151—227, 1901. 



'•) It might be tliought that tlie rays forming the chromosphere light, need to 

 be absent only from the spectrum of the edge but not from that of the central 

 portions of the Sun's disk. By a simple consideration, following from a look at 

 Fig. 4 of my paper, read in Febr. 1900 (Proc. Roy. Acad. Amst. II, p. 580) we 

 see, however, that the chromosphere light visible to us may very well, for a part, 

 have its origin even in points of the Sun which lie opposite to the Earth's direc- 

 tion. The chromosphere light, reaching the Earth, may proceed from a n y point 

 of Schmidt's "critical sphere". For the greater part it is likely to come from the 

 back half of the Sun. But tlien the half, facing us, furnishes the chromospheric 

 light which travels to other regions of the universe, and this light, of course, is 

 wanting in the spectrum of tlie disk. (There is some reason for supposing that, 

 on an average, more chromospheric light is sent forth in directions making great 

 angles with the Sun's equator, than to the equatorial regions, including the 

 Earth's orbit.) 



