RE: [Fwd: [Fwd: Re: Variable Capacitance and Inductance]]

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "David Thomson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <dave-at-volantis-dot-org>

Hi Dave,

>There is a differnc between absolute accuracy and trends.

Is this a euphemism for saying you agree that inductance and capacitance are
variable?

>> Why can't our "better instruments since then" give us exact inductance
and capacitance measurements?
>They do.  Or at least the best instruments, rigorously used, do.

Can you give me a reference?  Does this mean you believe a coil measured
with one of these instruments at one time will measure the exact same
inductance at all other times?

>> Could it be because inductance and capacitance are variable; just as
Tesla noted?
>Both are varied by surrounding effects.

If they are variable, then how do these accurate measuring devices get the
same exact result each time?  Even if you are saying the machines are
accurate and are measuring exact variations in inductance, that still agrees
with Tesla's assertion that capacitance and inductance are variable.

>'nothing'(on earth) exists in 'free space'.

Perhaps the more relevant observation is that "free space" has inherent
permeability and permittivity; the stuff that "makes" inductance and
capacitance.  This is why inductance and capacitance can be variable for a
material object such as a coil or capacitor.  The inductance and capacitance
of material objects is not entirely dependent on the characteristics of the
object, but also on the characteristics of the environment in which it
exists.

>In general Tesla	was not measuring capcaitince, but looking at some other
effect and assigning a variation to change in capacitiance.

That sounds just like how the "best instruments" you reference, work.  As
far as I know, there is not a machine on the face of this planet that
measures inductance or capacitance directly.

>For the values (small) worked with	by Tesla (when working with elevated
capacities), the measurement, with techniques available, is tricky.

No more than it is today.  Tesla built his own LC meters.  We buy them off
the shelf.  All that does is make LC measurements available to less
qualified people such as myself.

  > Dave P.>The variation in capacity of an isolated body (more or
  > less isolated, since altitude above earth seems mentioned) is
  > well known, falls out from the basic maths, and was, i believe,
  > known at the time, and earlier.

  > Malcolm W.>The assertion that the capacitance of the terminal
  > increases with height simply doesn't stand to reason (unless
  > it was just a few inches from the coil to begin with - mutual
  > shading). In elevating it (outdoors), he is moving it further
  > away from ground (closer to the ionosphere for sure, but
  > an absolutely trifling amount by comparison).

  > Now how come this is well known to you and Malcolm doesn't agree?
  > Are the engineers in our culture that divided over what is true
  > and what is not regarding variable capacitance and inductance?

	We are both 'describing the same elephant', from
	different perspectives.

Well then, since you and I agree that capacitance can be variable, and you
and Malcolm see "the same elephant," then we must all be in a agreement?
Somehow I don't think this thinking would be widely accepted.  Can you give
a clearer explanation as to how Malcolm and your views are the same?

>	cf 'magnetic amplifier'.

Ahh, yes.  Thanks.  I do remember reading about that.

>Also: 'a month of 16 hour days' (from another thread) tends to lead to
fatigue, and poor performance.

The truth is that Tesla went nearly his entire life at that schedule,
starting with high school.  Although Tesla did have several bouts with
disease and fatigue, he was quite productive for most of his 86 years; right
up to the end.  Other men, such as Thomas Edison, had difficulty keeping up
with Tesla's schedule.  Tesla adhered to the 16 hour day schedule the entire
time he was in Colorado Springs.  I don't think that improvement of brush
motors, the invention of all AC motors, the invention of high voltage
oscillators, and several other notable inventions are the result of fatigue
and poor performance.  Your unqualified criticism of Tesla is much like
Richard Hull's, it is based merely on personal opinion.

Dave