Re: plating xmas balls

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

Original poster: "Antonio Carlos M. de Queiroz" <acmq-at-compuland-dot-com.br> 

Tesla list wrote:

 > If I were to make some random surmises, rather than going down the hall and
 > actually getting the book that talks about this, think of this.  Arcs are
 > characterized by having a distinct "cathode spot" (or spots, depending on
 > current) where as the anode is more diffuse.  The temperature distribution
 > on the electrodes is very different.  The voltage distribution along the arc
 > is also not even, so the heat dissipation will vary.

What I see in an electrostatic machine spark, that is DC, is a
concentration at the positive end. This is visible in simple corona and
also in Leyden jar discharges. The negative side of a spark is brighter
and thicker in long sparks, but in short sparks, specially weak sparks
(not Leyden jar discharges), the positive side is brighter. Look at
these pictures. The positive side is at the right side:
http://www.coe.ufrj.br/~acmq/bbspark.jpg
And here the positive side is at the left side:
http://www.coe.ufrj.br/~acmq/waz12.jpg
If brightness is associated with heat, then probably the negative
terminal would get more heat. Really, the side where the electrons
hit the terminal.
But arcs from a welding machine are different from these.

Antonio Carlos M. de Queiroz