﻿in Total Eclipses of the Sun. 227 



port of the other hypothesis we have the well-established fact 

 that some form of luminous matter, belonging to eometary 

 bodies, when it comes under a certain degree of influence from 

 the sun, is projected or in some manner detached from the 

 nuclei of these bodies, and repelled from the sun, and under 

 the operation of the solar repulsion urged away from them to 

 an indefinite distance, forming the luminous trains by which 

 they are attended. (See the author's papers on Donates Comet 

 published in Silliman's Journal, Jan. and May, 1860, and July, 

 1861 ; and the discussion of the Dynamical Condition of the 

 Head of a Comet in the Number for Jan. 1859). To suppose 

 that the rays of the corona are actual radiations of luminous 

 matter, is only to suppose that a portion of the photospheric 

 matter of the sun becomes subject to the operation of the same 

 forces that we perceive the sun to exert upon a portion of the 

 matter of comets. The luminosity of such radiations may be 

 ascribed either to a reflection of the sun's light, or to electric 

 discharges. Upon this question, we shall see, important evidence 

 was obtained at the total eclipse of August 7, 1869. 



6. If we adopt the auroral theory of the corona, and at the 

 same time admit that the auroral streamers are actual emana- 

 tions of luminous matter, the following consequences may be 

 expected to follow. 



(1) A portion of the auroral matter emitted from the sun 

 should fall upon the earth's atmosphere, and may furnish the 

 substance of terrestrial auroras, for which no terrestrial origin 

 has yet been detected. 



(2) Upon this view of the possible origin of terrestrial 

 auroras, the close correspondence that has been detected be- 

 tween the periods of the sun's spots and of auroras should sub- 

 sist, if we allow that the spots are merely the natural result of 

 the supposed discharges of the solar matter, prevailing for a 

 time at certain points of the photosphere — or, indeed, if we grant 

 that they are in any way the result of these discharges visible in 

 the corona. 



(3) In the wave-propagation of the impulsive actions on the 

 ether of space of the electric discharges to which we may ascribe 

 the material emanations from the photosphere, and in the elec- 

 tric and magnetic phenomena attendant upon the reception and 

 accumulation of the solar auroral matter in our atmosphere, we 

 have a plausible general explanation of the periodic and irregu- 

 lar disturbances of the magnetic condition of the earth, and of 



Frankland, the solar atmosphere must be of exceeding tenuity in the 

 region of the rose-coloured protuberances, just above the general surface 

 of the chromosphere. 



Q2 



