the process of ionisation are sufficient' to carry them out of the sun's atmosphere, 

 a direct connection lid \\een sunspots and aurora 1 may exist. The continuous, or 

 almost continuous, influx of charged particles into the earth's atmosphere is thus 

 explicable, a circumstance which is probable, but which is difficult to explain on the 

 older theories.* 



\Xotr <l<ll /<'cl,i-H<iri/, 1!)22. Fleming (in : Nature/ of February, 1922) discusses 

 the projection of comparatively large charged particles from the sun by light pressure, 

 and the possibility that these will be brought to rest in the earth's atmosphere when 

 the density reaches the critical value at which tiictioiuil resistance rises lo its normal 

 value.] 



* Rayleigh has been able to photograph the green auroral line on most clear nights on these latitudes. 



11 



