Re: Tesla Receiver Coil

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Gary Peterson" <gary@xxxxxxxxxxxx>

Counsel

    I have read in some of your writings that you went to Colorado 
to further experiment with certain apparatus which you had tested to 
your own satisfaction at sea level. . . . was that demonstration 
undertaken in Colorado for the purpose of getting the higher altitude 
of the air?

Tesla

    No, it was nothing of the kind.  I simply went there because in 
Colorado my system of power transmission was introduced. . . . My 
experiments [on Houston Street] showed that at a height of 5 miles 
the air was in conduction to transmit the energy in this way, but my 
experiments in Colorado showed that at a height of 1 mile it is 
plenty enough rarefied to break down under the stress and conduct the 
current to the distant points.

    I have to say here that when I filed the applications of 
September 2, 1897, for the transmission of energy in which this 
method was disclosed, it was already clear to me that I did not need 
to have terminals at such high elevation, but I never have, above my 
signature, announced anything that I did not prove first.  That is 
the reason why no statement of mine was ever contradicted, and I do 
not think it will be, because whenever I publish something I go 
through it first by experiment, then from experiment I calculate, and 
when I have the theory and practice meet I announce the results.

    At that time I was absolutely sure that I could put up a 
commercial plant, if I could do nothing else but what I had done in 
my laboratory on Houston Street; but I had already calculated and 
found that I did not need great heights to apply this method.  My 
patent says that I break down the atmosphere "at or near" the 
terminal.  If my conducting atmosphere is 2 or 3 miles above the 
plant, I consider this very near the terminal as compared to the 
distance of my receiving terminal, which may be across the Pacific. . 
. . I saw that I would be able to transmit power provided I could 
construct a certain apparatus. . . .  I have constructed and patented 
a form of apparatus which, with a moderate elevation of a few hundred 
feet, can break the air stratum down.  You will then see something 
like an aurora borealis across the sky, and the energy will go to the 
distant place. . . . An apparatus which permits displacing a certain 
quantity of electricity in the terminal . . . will produce an 
electric potential at a distance of 5 miles, and the fall of electric 
potential per centimeter will be equal to the quantity of electricity 
divided by the square of the distance.  Now, I have satisfied myself 
that I can construct plants in which I may produce, per kilometer of 
the atmosphere, electric differences of potential of something like 
50,000 or 60,000 volts, and at 50,000 or 60,000 volts that atmosphere 
must break down and will become conductive.

    So that, when I had explained this principle to Lord Kelvin, he 
became absolutely convinced that I could do it; but Helmholtz was 
convinced from the very beginning that I could do it.  It took 
argumentation, however, and demonstration by experiments, to convince 
Lord Kelvin. -- Nikola Tesla, 1916