Re: Tesla's CS Coil Data from ScanTesla and all....

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Terry Fritz <teslalist@xxxxxxxxxxxxxxxxxxxxxxx>

Hi,

At 12:35 AM 6/28/2005, you wrote:
> ............
>
>     John, are you, well, absolutely certain on this? The reason is I have 
> read the "120 foot" (40 meter) figure so many times. Please understand 
> I'm just double checking with you; this is the first time I personally 
> have seen the 33 feet number. Again, I am not arguing with you, I am just 
> very surprised!

Tesla's primary/secondary coils were exactly 15 meters in diameter (49.2 
feet) and 6.5 feet high.  His eight foot diameter secondary was in the 
center.  That gives about 20 of clearance in the radial direction.  The top 
of the Third coil stood 12.5 feet high or 6 feet higher than the top of the 
secondary.  Sqrt(20^2 + 6^2) = 20.9 feet point to point clearance (page 203 
CSN).  His lab walls and roof were not much further away.   A 21 foot 
streamer should need about 11kW of streamer power.

So, the bottom line is he didn't have room to get a 100 foot point to point 
streamer.  He didn't have the power either...  None of the many pictures of 
the CS coil in action ever showed a streamer over 22 feet and most were 8 
to 10 feet...  The bottom of page 330 of the CSN notes tells it all...

"These streamers were about the longest producible in the present building, 
with the roof closed, measuring from 31 to 32 feet in a 'straight line' 
from origin to end.  Taking into account the curiously curved path the 
length was probably more than twice this, so taking the discharge from tip 
to tip of these longest streamers, the actual path of the discharge through 
the air was from, say, 124 to 128 feet!"

So he had 32 foot streamers with 64 foot path lengths.  His 124 to 128 foot 
"tip to tip" number was the streamers diameter around his coil with the 
path length included....  Streamers 64 feet to the left, and 64 feet to the 
right ;-))  He goes on to speculate about 384 foot streamers but he never 
"did" that....  Bottom line is, they were 32 feet.....  I note when Tesla 
uses the word "discharge", he means the total length side to side covered 
by the streamer paths...  That is say 4X the real streamer distance not 
counting the diameter of the discharge structure.


So were do the 100 foot numbers come from?  Probably from articles like this:

http://www.pbs.org/tesla/res/res_art09.html

"I have produced electrical discharges the actual path of which, from end 
to end, was probably more than one hundred feet long; but it would not be 
difficult to reach lengths one hundred times as great."

One spark length picture in that article Tesla seems proud of:

"The discharge escapes with a deafening noise, striking an unconnected coil 
twenty-two feet away"

Assuming he is like us and saw a far hit and grabbed a tape 
measure....  It's 22 feet....

There were obvious errors:

"The flame-like discharge shown in the photograph measures sixty-five feet 
across." - page 334, Photograph X.

That is about 24 foot feet actually with the eight foot coil in the middle 
and eight foot streamers off the sides....  so change 65 feet to 8 
feet...  It was a long time exposure too ;-))  He did have a few longer 
hits to the lower left.

One should read these articles and especially the last where John O'Neill 
eludes to how difficult it was to get "real" information out of Tesla 
during interviews.

"To this end I sought to gain some insight into his thoughts, that would 
enable me to get a practical plan into operation. This was no secret to 
Tesla and he successfully parried every thrust I made. "

http://www.pbs.org/tesla/res/res_arts.html

The style and tone to these articles in a stark contrast to the pure 
technical and highly detailed writing in his CS notes!  If one reads the 
clear writing starting on page 127, one notes that he could write in a very 
detailed and straight forward way.

Tesla said a lot of things for a lot of reasons...  But one has to really 
read a lot of his work to separate the "solid technical details" from his 
great speculations...  Read the articles on the PBS sight and the Colorado 
Springs notes to get an idea of the wide "variety of facts" in even things 
Tesla directly wrote.  I would not trust second hand accounts at 
all...  Tesla could make others believe anything he said and that is before 
they add their own imaginings to his words...

Tesla did many great things!  He sometimes said he did greater things. He 
imagined far greater things still...

Cheers,

        Terry