Re: 1939 Worlds Fair GE Exhibits

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: David Dean <deano@xxxxxxxxxxxxxxxx>

Hi

Thanks for explaining how it worked. I was confused about the color and the
odd third spot that seemed to be on fire.

"Tangential
> to each ball was a sharp pointed half tube that held a colored fusee"

Of course.

Now after pondering this thing frame by frame for---
Well. long enough now. Time to sleep//

by the way, for your amusement...    http://deanostoybox.com/temp/

On Saturday 21 October 2006 14:48, you wrote:
> Original poster: Bert Hickman <bert.hickman@xxxxxxxxxx>
>
> Curt, Ben, and all,
>
> Curt - thanks for the excellent pictures! And
> Ben, we'd love to see a scan of the picture you
> have. Following is a portion of my posting about
> the GE World Fair exhibit from last June on the HV List:

snip
>
> The million volt 3-phase arc was powered from a 1500 hp motor-generator
> set, and used reactive current limiting. Open circuit voltage across
> phases ranged from 850 kV to 1 MV. Six 350,000 volt cascade transformers
> were used, each with a rating of 1,000 KVA, with pairs connected in
> series-cascade to generate 700,000 volts to ground or about 1.2 MV
> phase-to-phase. The grounded (bottom-most) transformers each had a
> tertiary 2300 volt winding which drove the LV side of the floating
> transformer.
>
> Each floating transformer sat on a 5 foot high insulating pedestal and
> operated at 350,000 volts above ground. The diameter of each transformer
> was 85.5" and overall transformer height including insulator was 14 feet
> 10.5". The transformers were designed to harmlessly arc over the output
> bushing at 450,000 volts and to safely withstand transient impulses of
> over 1.3 MV. Images of one of these transformers undergoing 450 kV
> dielectric and 1.3 MV impulse testing follow, and I've also included an
> image of a single-phase million volt arc:
> http://205.243.100.155/photos/GE_Lab/XfrmrArc.jpg
> http://205.243.100.155/photos/GE_Lab/1mevarc.jpg
>
> Electrodes for the three phase arc were mounted on 18 foot insulating
> masts, and the masts were arranged to form an equilateral triangle 14
> feet on a side. Each electrode consisted of a spinner electrode (a bar
> mounted on ball bearings and tipped with 5" balls on the end. Tangential
> to each ball was a sharp pointed half tube that held a colored fusee
> which served to color the arc as well as increase its length. Corona
> drove the spinners like giant pinwheels at 50-100 RPM depending upon the
> length of the spinner. Two interchangeable length spinners (3 foot and 5
> foot) were used. The minimum distance between spinners was between 9 and
> 11 feet depending upon the length of the spinner that was used. Once
> ignited, the arc rises 20 feet above the gap in a tortuous path
> estimated to be between 100-150 feet long.
>
> Unfortunately, I haven't had any success in locating good pictures of
> the spinning 3-phase arc. One picture (unfortunately very small) of a
> static arc can be seen here:
> http://205.243.100.155/photos/GE_Lab/3-Phase_Arc.jpeg
>
snip

> >  >I came across the following searching for information regarding a
> >  >Tesla coil my Dad says he saw at the 1939 world fair. I didn't find
> >  >the Tesla coil, but found what looks like a jacob's ladder with
> >  >rotating electrodes. Not specifically Tesla related, but thought the
> >  >group would enjoy:
> >  >
> >  >Still pictures:
> >  >http://www.pmphoto.to/WorldsFairTour/Zone-5/090.htm
> >  >
> >  >Video:
> >  >http://www.archive.org/details/Medicusc1939_3
> >  >
> >  >It's a fascinating display, looks like it might be three phases
> >  >arcing together? No sure what to make of it.
> >  >
> >  >If anyone has any detail of a Dr. Moon at the fair, please let me
> >  >know. Apparently he would stand on the top of his coil and let the
> >  >streamers come from his fingers.
> >  >
> >  >Curt.
this   http://www.pupman.com/listarchives/1997/march/msg00271.html

later

deano