Re: Tesla myths corrected - Best text? (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Tue, 23 Oct 2007 19:53:06 -0700
From: James Zimmerschied <zimtesla@xxxxxxx>
To: Tesla <tesla@xxxxxxxxxx>
Subject: Re: Tesla myths corrected - Best text? (fwd)

Peter and all,
 A book that I have found useful in dealing with some of the claims about
Tesla's work is "Nikola Tesla On His Work with Alternating Currents and
Their Application to Wireless Telegraphy, Telephony and Transmission of
Power" compiled by Leland Anderson Twenty First Century Books. This book
is a transcription of depositions by Tesla to his counsel in preparation
for court actions related to his inventions. The transcripts are very
interesting because the counsel was technically astute and he pinned Tesla
down on many claims and brought out details of how the various apparatus
worked.

In the Anderson book on pg 98 Tesla is discussing transmission of power to
light a bulb some distance away. The photo shows a small lighted bulb
attached to a large coil which was in a field. Tesla states the distance
is not important since the power was not carried by electromagnetic waves
but by a ground current. When pressed on how far the bulb/coil was from
the main circuit Tesla states "I cannot tell you but the complete details
were illustrated in Century Magazine". A footnote in the book states that
the article in Century Magazine did not give any distance information.

On the other hand in John O'Neill's book "Prodigal Genius" on page 193-194
is a claim that Tesla lit 200 50W bulbs at a distance of 26 miles (10000 W
or 13 hp). The book says the information was from "piecing fragmentary
information published in various publications..." No direct quote from
Tesla.

Another good book that is out of print but may be found on the internet is
Richard Hull's "The Tesla Coil Builder's Guide to the Colorado Springs
Notes of Nikola Tesla". Here is one example: In "Prodigal Genius" the
story is related of the Colorado Springs apparatus discharging lightning
bolts 80 feet or longer from the tall mast with a ball on the end (pg
186). Tesla is quoted as saying the "discharges were probably 100 ft end
to end and it would not be difficult to reach lengths 100 times as great"
(pg 188).

Hull in his analysis of the Colorado Springs apparatus and laboratory
noted that the distance from the pole mast to the building surrounding it
would not have allowed a long discharge from the mast. Also Hull doubts
that any discharge more than 43 ft end to end based on Tesla's notes. No
photos were made (or preserved) of a discharge from the mast. Also the
capacitance of the mast and ball were such that it would have been
unlikely that Tesla could have brought it into resonance with his
equipment.

Other biographies tended to also include information contained in the
earliest one from O'Neill. The bottom line is that there was a lot of myth
mixed with the facts. Jim Zimmerschied


  ----- Original Message ----- 
  From: Tesla list<mailto:tesla@xxxxxxxxxx> 
  To: tesla@xxxxxxxxxx<mailto:tesla@xxxxxxxxxx> 
  Sent: Monday, October 15, 2007 8:45 AM
  Subject: Re: Tesla myths corrected - Best text? (fwd)



  ---------- Forwarded message ----------
  Date: Mon, 15 Oct 2007 22:59:19 +0800
  From: Peter Terren <pterren@xxxxxxxxxxxx<mailto:pterren@xxxxxxxxxxxx>>
  To: Tesla list <tesla@xxxxxxxxxx<mailto:tesla@xxxxxxxxxx>>
  Subject: Re: Tesla myths corrected - Best text?

  I have had the need on several occasions now to correct myths about Tesla 
  but lack the knowledge base. Does anyone recommend a book that will have 
  this sort of information.

  Things like
  "Lit up 200 light globes at 40 miles."
  Hard to conceive doing this even with a wire.  Think about it in terms of 
  wire resistance for DC particularly if only conventional mains voltages.
  Suppose light globes are 100V 50W  then 200 x 50W = 1kW. At 100V this is 
  10A. Even 10 ohms will be a major problem and would require very thick wire 
  to get 0.25 ohms per mile. 2 Two strands of 0 SWG = 9mm thick would do this. 
  And this is just one way.  It assumes a very good earth is available at both 
  ends.  Use one strand of 9mm and you will light up the globes at 1/4 current 
  and perhaps 1/10 brightness.
  At current copper prices that is something like $14,000. Not counting 
  supports etc.
  Using low frequency AC allows voltage step up then the supports become 
  important and you need to run transformers at either end.  And using high 
  frequency or even Tesla output is out of the question due to corona, 
  capacitative and inductance issues.
  To do that as a wireless setup even with a mile high transmitter and 
  receiver and resonant setup would seem far fetched to get that sort of 
  performance

  I understand that this was press hyperbole that has grown by word of mouth. 
  I recall someone stating that the original experiment was that he lit up 
  some globes just outside the lab earthed to a pipe.  I don't have the 
  background for that.

  Similarly, Tunguska explosions, death rays, resonant vibrations and 100MV 
  sparks are all ludicrous.

  Can anyone help direct me?

  Peter