PROCEEDINGS 1^ 
OF THE ^ , ^ - 
NATIONAL ACADEMY OF SCIENCES 
Volume 3 JANUARY 15.1917 Number 1 
INFERENCES CONCERNING AURORAS 
By Elihu Thomson 
GENERAL ELECTRIC COMPANY. WEST LYNN. MASSACHUSETTS 
Read before the Academy November 14, 1916 
It seems doubtful if any extensive auroral display has occurred with- 
out coincident existence of exceptional areas of disturbance on the sun. 
We may assume that at such times great jets or streams of electrified 
matter (electrons perhaps) akin to cathode rays in a vacuum, are pro- 
jected with high velocities outward, and that occasionally some of 
these jets cross the earth's orbit or pass near to it, being when leaving 
the sun in a general radial direction, bent backwards for obvious reasons. 
That electrified matter in a vacuum does move in jets or streams for 
indefinite distances is a fundamental fact. Moving charges of the 
same name in paths, straight or curved, act like parallel currents and 
attract one another, the more as their velocity is greater, until the static 
repulsion of such like charges sets a limit to further approach. It is 
possible that the space around the sun may be crossed by many such 
jets or streams of electrified matter moving at very high velocities into 
the vacuous space. The coronal streamers may be the visible composite 
effects of the projected jets. Such electrified jets may act inductively 
by proximity to the earth or directly by conduction of electricity to the 
earth's outer atmosphere. 
In the present paper, however, it is hoped to prepare the way for 
further study by pointing out certain physical facts regarding the re- 
lations of auroral phenomena to the earth and its atmosphere: to 
locate and give direction to the streamers seen in auroras; and to ex- 
plain the nature of the so called auroral arch, the zenith crown, and 
other characteristics. It is believed that the following propositions 
may be shown to be true. 
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