204 PROF. O. REYNOLDS ON AN ELECTRICAL CORONA 



are not all of them straight or perpendicular to the sun's 

 surface. 



Such bright rays as these cannot be the result of the 

 sun's light or heat acting on an atmosphere or on matter 

 circulating in the form of meteorites. If they are due to 

 the action of the sun's light or heat at all, the matter on 

 which these act must be distributed in the rays we see; for 

 the sun's light and heat coming out uniformly all round 

 would illuminate any surrounding matter, if at all, so as to 

 show its figure. 



The picture irresistibly calls up the idea of a radial 

 emission. If it is the picture of distributed matter, that 

 matter must exist in the form of streams leaving the sun ; 

 if it is the picture of some light-producing action, this also 

 must exist in the form of an emission from the sun. 



Such, then, are the extraordinary features of the solar 

 corona ; and, as I stated, they resemble those of an elec- 

 trical corona. Any one who is familiar with the various 

 forms of electrical disruptive discharge will recognize the 

 general resemblance these coronal features bear to an 

 electric brush. But to the electric phenomenon I am 

 about to describe it is no mere general resemblance ; it is 

 an actual likeness, with every feature identical. 



Before describing this phenomenon I may be allowed to 

 state how I came to notice it. It will be remembered that 

 in a former communication to this Society I ascribed the 

 phenomena of comets and the corona to a certain electrical 

 condition of the sun. Well, the peculiar appearance of 

 Mr. Brothers's photograph induced me to try if a brass ball, 

 brought into the condition I had ascribed to the sun, 

 would give off a corona presenting this appearance. 



The phenomenon is produced by discharging electricity 

 from a brass ball in a partially exhausted receiver. To do 

 this there is no second pole used, the objects which sur- 

 round the outside of the glass probably answering for this 



