* Carbons Sent to: Esondrmn-at-aol-dot-com

Quoting Ed Sonderman:

 ES> The son of a friend of mine wants to do a research paper on 
 ES> lightning and particularly ball lightning. I have seen comments 
 ES> here in the past about making ball lightning using a tesla coil.  
 ES> Has anyone done this before? 

 ES> If you have any sources for research material on this subject I 
 ES> would appreciate some help.

Yes, this has been done by Tesla, and by Kenneth L. Corum and James
F. Corum, who were the first people to my knowledge to accurately 
decipher Tesla's sometimes crypic notes and reproduce Tesla's orignal 
experimental method. Corum & Corum published in the Tesla Coil Builders
Association publication "NEWS" Volume 8, #3--July, August, September--
1989, "Tesla's Production of Electric Fireballs", pp 13-18. This article
includes four B&W photos, one page of apparatus schematics, and an 
extensive bibliography. It is available as a back issue from the TCBA. 

In addition Corum and Corum published a more lengthy paper in 1988 titled:
FIRE BALLS - A Collection of Laboratory Experiment Photographs; which
consists of text plus 36 color photographs and commentary, 50 pp total
for $55.00 and available from: Corum & Assoc. Inc., 8551 State Route 534
Windsor, OH 44099.

Tesla, of course, was the first person that I am aware of to produce 
electrical fire balls in the laboratory. Tesla shows dozens of diagrams
and photographs of apparatus capable of producing fireballs in the 
COLORADO SPRINGS NOTES (or CSN). See the notes and diagrams on pp 
114-115, 174, 176, 177, text on pp 368-370, etc... 

The CSN is liberally sprinkled with circuits and techniques for fire
ball production; the problem being that Tesla does not show a wiring 
diagram and say "This circuit produces fireballs." The circuits he 
used are diagramed in the course of the notes, but the discussion of 
fireballs appears in different sections with no clear connection to a 
particular circuit schematic. The key to understanding the versitility 
of these circuits is in realizing that the main coils were large and 
difficult to move. However, by simply moving the base lead wires around 
and adjusting the dischargers and tank circuit tune, it was easy to fire 
a Magnifier configuration one minute, and a fire ball machine the next.
(well a few minutes anyway!)

By Nikola Tesla... Hardcover, 440pp, Published by NOLIT, Beograd,
Yugoslavia, 1978. Prefaced and annotated by Aleksandar Marincic, 
Assoc. Prof. of EE Beograd Univ. and advisor to the Nikola Tesla 
Museum, Yugoslavia. 

BTW, the fireball circuit basically consists of two secondary coils
with substantially different frequencies (say 67 kHz & 156 kHz) 
coupled to the same tank circuit. The Corums used a primary coil 
shaped like an oval racetrack (or a modern football stadium) with 
the two secondary coils positioned inside. Points are generally 
added to the coil dischargers to force the two coils to strike one 
another. Carbon vapor assists in the production of a stable plasma 
sphere, so the discharger points are doped with carbonaceous material.

Richard Quick

... If all else fails... Throw another megavolt across it!
___ Blue Wave/QWK v2.12