( rm ) 



(loüree. Tlioii. tlio rofractivo iiidicos ot'llio iioiii-lihouriiiLi' \va\os diflferiiiii; 

 liardly from iiiiily, llio diivclictii of lliosc rays will (»iih- he pcrcep- 

 til)ly cliaiiued after lliey havo IraNcUcd a \rv\ Ioiil>' way tliroiiiili 

 llio corona aiid aliiutst parallel lo its sti-u('liir('diji(\s. Wiieroas llie 

 slroiiiily rofracled rays, eiileriiiu- \\io coi-oiial streamer in \arious 

 diroctioiis, wei-e ohlig'ed to follow \Uo stnictiire-liiies, curving about 

 them, and so in a sense were concentrated on the Earth, it may 

 hapi)e]i with tlie extremely sliulitly cnr\ed rays we are now consi- 

 dering-, that tliey have l)een bent for instance oidy once over the 

 whole length of the streamer and continue their way in a direction 

 not meeting the observing station. The divergence of a beam con- 

 sisting of these rays will have inci'eased, tiie intensity diminished. 

 Thus, the i-esultaiit spreading of neighbouring light causes the 

 absorption line to ap|)ear somewhat widened and therefore strengthened. 

 l)Ut obviously it must be j)ossible too, that, after a short time, under 

 the influence of another i)art of the corona, circumstances turn out 

 even favoui-able for that slightly curved light to reach the observer. 

 In that case the absorption line is weak again. (.Similar alternations, 

 of course, also occur with the more strongly refracted rays, and that 

 in ([uicker succession, but this does not alter the fact of their /'/yv-'ym/t' 

 intensity appearing increased as long as the structure lines of the 

 coronal streamer are turned towards the spectroscope. For a detailed 

 dis(aission of this case see the Note at the end of this pa[)er). 



In both abnormal specti'a a number of al)sorption lines are more 

 or less displaced. Perhaps this is partly due to motion in the line 

 of sight; but after the foregoing it will not be necessary to exjtlain 

 in detail, that also anomalous divspersioji can account for this ])heno- 

 menon. Dissymmeti'ic form of the dispersion- curve as well as a 

 peculiar distribution of the density of the coronal matter may une- 

 ([ually affect the intensity of the light on both side^s of the absori)tion 

 line, and thus bring about a seeming displacement of the line. 



Certain j)eculifn'ities of //'nes in the nonnal solar speet rum. 



If we have been right in connecting the uiu'ommonly great abnor- 

 malities in Hale's spectrum with a very particular position of the 

 Earth with resj)ect to the corona, it is to be expected that similar 

 ii'i'egularities, though to a smaller degree, will e\er be found, as the 

 sunlight always reaches us through the coi'ona. 



According to Je\veij/s above mentioned investiga'ions this supposition 

 [)roves to be well founded. Many solar lines have varying intensities 

 and positions, so that .Ikwkll <leems them inilil for standards for 



