Eclipses 



contrary, the very great activity of the sun 

 corresponded with a greater extension of the 

 gaseous corona. 



Is this variation connected with a change 

 of the actual gaseous mass or simply with a 

 modification of its luminosity? It is difficult 

 to accept the first hypothesis in consideration 

 of the enormous quantity of gas which would 

 have to be ejected by the central regions during 

 periods of solar activity to be reabsorbed during 

 quiescence. Scientists have therefore adopted 

 the second, for the time being, but even 

 then there are many divergences of theory. 

 Some consider the gaseous corona to be a mass 

 heated to a high temperature, probably some- 

 thing like three thousand degrees, and luminous 

 owing to its high temperature; others fall back 

 upon electrical phenomena for an explanation. 

 It is probable that the internal agitation of these 

 bodies of gas is either the cause or the effect 

 of electrical actions, of which the storms of our 

 atmosphere can suggest but a very poor idea. 

 It is, in any case, reasonable to suppose that 

 these solar storms are most powerful during 

 periods of maximum activity and are accom- 



N 213 



