# RE: Variable Capacitance and Inductance

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

Hi Terry,

>If Tesla's data can be extracted, we may be able to determine what his
setup was as long as the measurements of "it" were accurate.  If we have
data points, we may be able to find the situation that matches it.

The table on 209-10 is revealing.  The values he chose to record show us
many of the key points of his setup as he defined them.

>I was worried about posting it since it was sort of a flame.  Glade to see
you responded calmly :-)  That puts out the flames real fast :-))

I still have great respect for Paul and everyone else on this list.  He is
an expert, no doubt.  But like Tesla and the rest of us, he too can make
errors; even if they are just errors in judgment.

>>>What would be needed is a clear table for values of the 30 inch sphere's
elevation vs. capacitance with the wire there.  like this:
>>I'll get to this later.  I've got to leave for a bit.
>That would be great.  That would provide a solid starting point "we" could
"all" understand.

>From pages 293-4 Tesla measured the capacitance of a 30" ball with the
following measurements:

height   capacitance
--------  --------
10'1"    15.75pF
33'8"    18.33pF
57'3"    20.95pF

I mentioned before the possibility that Tesla might be measuring some of his
capacitance as vertical versus horizontal.  He does this on pages 294-6.
This is just for the wire, however, and not with the ball.  He uses a 10
meter wire with capacitance measured at horizontal 8'8" above the ground and
then vertical with the lowest point at 8'8" above the ground.  He does this
same experiment twice, once with a primary induction of 17.5 turns and then
again with a primary induction of 6.625 turns.  The readings do not agree as
he thought they would.

Turns of Primary   Horizontal      Vertical
17.5                104.80pF        62.74pF
6.625                74.79pF        72.51pF

(I gave turns of primary instead of inductance as a reference only.) He
mentions that he intends to look at this more closely later.

Dave

```