CD 1966007 E&MP27.089
no date (possibly 1934-39)
This great, crystal-clear globe produces a weird and startlingly brilliant yellow and purple display akin to a miniature pyrotechnic bonfire.
It all takes place when particles of sodium tossed from the pool at the base of the globe become electrically charged and rise against gravitation in the electric field of the discharge.
Each particle is bathed in its own golden cloudlet of glowing sodium vapor as it moves upward in the main arc stream and then curves gracefully outward, fading as it approaches the surface of the globe.
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Original Caption by Science Service