[Prev][Next][Index][Thread]
Re: Moody Bible Inst. Tesla Coil (fwd)
---------- Forwarded message ----------
Date: Mon, 24 Feb 1997 00:10:56 -0800
From: Bert Hickman <bert.hickman-at-aquila-dot-com>
To: Tesla List <mod1-at-pupman-dot-com>
Subject: Re: Moody Bible Inst. Tesla Coil (fwd)
Tesla List wrote:
>
> ---------- Forwarded message ----------
> Date: Sun, 23 Feb 1997 20:35:30 -0500
> From: Thomas McGahee <tom_mcgahee-at-sigmais-dot-com>
> To: Tesla List <mod1-at-pupman-dot-com>
> Cc: robert.michaels-at-online.sme-dot-org
> Subject: Re: Moody Bible Inst. Tesla Coil
>
> > >
> > > Subscriber: robert.michaels-at-online.sme-dot-org Thu Feb 20 22:50:16 1997
> > > Date: Wed, 19 Feb 1997 23:04:08 GMT
> > > From: Robert Michaels <robert.michaels-at-online.sme-dot-org>
> > > To: tesla-at-poodle.pupman-dot-com
> > > Subject: RE: Re: Secondary CURRENT
> -snip snip snip-
> > >
> > >
> > > Your post reminds me of some spectacular demonstrations
> > > conducted by the Moody Bible Institute of Chicago. The
> > > last of these which I recall occurred some 25 years ago.
> > >
> > > The Institute had a medium-sized theatrical coil, secondary
> > > about 3 x 5 ft. It must have been tube-powered because it
> > > was dead silent save the (relatively quiet) discharges.
> > > This coil had a flat-plat as terminus.
> > >
>
> Robert, that particular coil was most likely the same one I described
> in a recent post. I saw it in 1964 at Patrick Air Force Base in Florida.
> It was powered by a modified Marx generator. The reason it sounded so
> silent was that the spark gap sections were all enclosed in a double-sealed
> case to reduce both the spark noise and the light usually emitted
> by the apparatus. Besides the Tesla coil they also demonstrated a tuned-rod
> sound detection system that allowed you to hear a person whispering
> several hundred feet away, and a see-in-the-dark scope using a 6032 infra
> red image tube. The person doing the demonstrations controlled many of the
> pieces of equipment with a sort of rotary telephone dial that he had
> attached to his belt.
>
> The Tesla coil was the real show-stopper! They sometimes attached something
> like
> a cherry bomb to the top of the coil so that when they turned it on there
> was
> an explosion at the top of the coil. This unexpected explosion really made
> people
> jump in their seats! I believe they stopped doing that in some of the later
> shows. Probably didn't want any heart attacks in the audience!
>
> > > In a typical demo, a large metal bowl was first placed on the
> > > flat plate and the coil energized. Arrogant blue-white
> > > streamers 3-4 ft. long danced around the rim of the bowl
> > > and clawed their way into the atmosphere.
> > >
> > > Next, the bowl was removed and a man stood barefoot (but
> > > otherwise fully clothed) atop the flat plate. When the
> > > coil was again energized, he was enveloped in a hissing,
> > > sizzling brush discharge.
> > >
>
> Sometimes he would step into a foot bath of salt water before standing
> on the plate to get a better electrical connection. They had also
> experimented with a special kind of shoe, but it turned out to be
> easier to just do it barefoot.
>
>
> > > The power was cut and he was handed a two-by-four the bottom
> > > foot or so of which had been wrapped in foil. This was held
> > > overhead, vertically, with both hands. The power was again
> > > applied. A discharge worked its way up from the foil and
> > > along the two-by-four. After a few moments the wood began
> > > to first smoke and then ignite.
> > > - - - - - - -
> > > On one occasion I was privileged to talk to the demonstrator
> > > after the show and learned a few tricks of the trade. For
> > > one, it's essential not to have any metal about one's person,
> > > the fly of one's trousers included. For another, a heavy
> > > pencil line (invisible to the audience) had been drawn along
> > > the length of the two-by-four.
>
> The demonstrator once accidentally did the demo with a few coins in his
> pocket, and got some nasty RF burns from the coins, and literally
> burned a hole in his pocket!
>
> Another thing that he sometimes did with the two-by-four was to drive a
> long nail into the end of the two-by-four where he held it with the
> SEVERAL layers of aluminum foil. This would cause the arc to issue
> from the inside of the wood, sometimes rather startlingly. They
> switched to the method of using an external pencil line after one
> particular pine two-by-four literally exploded from the internal
> steam generated by the heat.
>
> By the way, when the two-by-four began to burn, the arc would follow
> the path of the flame and rose sometimes as high as 20 feet due to the
> ionization caused by the flame. I mention this because it is very
> dangerous.
> A Tesla coil that will normally only throw a 4 foot streamer will throw
> a much longer one vertically when the air is ionized by a flame. If you are
> not careful, this ionized streamer can readily reach up to the ceiling of
> an auditorium and pass excessive RF currents over the body of the
> demonstrator.
>
> Fr. Tom McGahee
>
<SNIP>
Fr. Tom and all,
When I was a kid growing up in Milwaukee Wisconsin, I saw this
demonstration! This was back in about 1958 or so. The guy's name was
George Speak if I remember correctly, and he was an
evangelist/scientist. He put on one _fantastic_ show, weaving science
and religion together. The grand finale was with him standing atop the
coil, with lightning coming off his fingertips (which had thimbles on
them for protection). They advertised this as a 1 Million Volt coil
(although it was probably actually less than half that). But incredibly
impressive it was!!
Although I was interested in science and electronics before this, the
demonstration helped put me firmly onto a career in electrical
engineering, and a continuing fascination with Tesla Coils! It's been
almost 400 years before I finally know the details about how this coil
actually was designed!! Thank you Tom!
Anyone know whatever became of this rig??
-- Bert --