ELECTRIC CURRENTS AROUND THE SUN. 47 



In the operation of an inductive electrical machine, 

 the disc which is at rest is independently excited 

 by friction, so that it will react when the other 

 disc is turned opposite to it. In the operation of 

 the solar system, instead of an artificial excitation, 

 as of the disc at rest, the great central orb is ex- 

 cited by a swift rotation on its axis (with a surface 

 velocity at the equator of seventy-four miles per 

 minute), opposite to the several planets, each sim- 

 ilarly excited by rotation on its axis. 



This axial rotation induces electric currents 

 around the sun, and arouncl each of the planets ; 

 which thus become polarized. 



With the extraordinary magnitude of the cen- 

 tral orb, combined with its * extreme velocity of 

 rotation, a correspondingly greater intensity of 

 electric excitation of the solar electro-sphere is to 

 be anticipated. These anticipations are confirmed 

 by the observations of astronomers during total 

 eclipses of the sun, while the dark disc of the 

 moon screens its dazzling brightness, and leaves 

 visible only the extreme ring of light, denoted " a 

 corona? Observers have described this corona 

 as exhibiting coruscations, wildly darting off far 

 beyond the extreme edge of the solar disc, flash- 

 ing thousands of miles in tongues of flame. This 

 description corresponds with the flashings and cor- 

 uscations occasionally appearing in the aurora 

 borealis above the earth's atmosphere. Between 

 the luminous flashings over the surface of the 



