28 SCIENCE IN SHORT CHAPTERS. 



tions, what must be that of the solid projectiles, and where 

 must they go? 



A cosmicai cannonade is a necessary result of the condi- 

 tions I have sketched, and as prominence-ejections are con- 

 tinually in progress, there must be a continual outpouring 

 from the sun of solid fragments, which must be flung far 

 beyond the limits of the gaseous prominences. As the 

 luminosity of these glowing particles must be very small 

 compared with that of the photosphere, they will be in- 

 visible in the glare of ordinary sunshine ; but if our eyes be 

 protected from this, they may then be rendered visible, 

 both by their own glow and the solar light they are capable 

 of reflecting. They should be seen during a total eclipse, 

 and should exhibit radiant streams proceeding irregularly 

 from different parts of the sun, but most abundantly from 

 the neighborhood of the spot regions. As these spot re- 

 gions occupy the intermediate latitudes between the poles 

 and the equator of the sun, the greatest extensions of the 

 outstreamiugs should be N.E. and S.W., and S.E. and 

 N.W., while to the N., S., E., and W. that is, opposite 

 the poles and equator of the sun there should be a lesser 

 extension. The result of this must be an approximation to 

 a quadrilateral figure, the diagonals of which should extend 

 in a N.B. and S.W., and a S.E. and N.W. direction, or 

 thereabouts. I say "thereabouts," because the zone of 

 greatest activity is not exactly intermediate between the 

 poles and the equator, but lies nearer to the solar equa- 

 tor. 



Examined with the polariscope, these radiant streams 

 should display a mixture of reflected light and self-lumi- 

 nosity. Examined with the spectroscope, a faint continu- 

 ous spectrum due to such luminosity of solid particles 

 should be exhibited, with possibly a few lines due to the 

 small amount of vapor which, in their glowing condition, 

 they might still give off. Besides this, there should appear 

 the spectroscope indications of violent electrical discharges, 

 which must occur as a necessary concomitant of the furious 

 ejections of aqueous vapor and solid particles. All these 

 metallic hailstones must be highly charged, like the parti- 

 cles of vesicular vapor ejected from the hydro-electric ma- 



