On Oct 23, 2:48*pm, Ian Jackson
wrote:
In message , Cecil Moore
writes

Szczepan Bia³ek wrote:
It is a history: "In the early days of lightning conductors, I
believe that the French
didn't like the nasty pointy things which the British had installed.
Instead, they decorated theirs with fancy balls at the top - with
sometimes disastrous results.

I assume a certain biased reporting of anecdotal evidence.:-)

A ball at the top hat of a Tesla coil allows a greater
amplitude of voltage to build up before arcing than does
a point at the top. Therefo

Points should result in more lightning strikes at lower
voltages.

Balls should result in fewer lightning strikes at lower
voltages.

Did you mean 'higher'?

Can't think of any valid reason why either design
should be able to avoid the really big one.

Surely, when lightning is about, points allow an essentially continuous
discharge at a low current, while balls allow the voltage to build up
and up, until there is a big 'splat'?
--
Ian

In the end, that's about the way I see it, but I consider
any discharge by either to really be fairly irrelevant.
Trying to avoid strikes by discharge is like whizzing in
a whirlwind. :/
The sharp point streams much easier than the ball,
so the chances of streaming and connected to a down
leader are much greater than with a ball which will
resists streaming at those same potentials.
If you had a spike next to a ball, I would think the spike
would be struck most of the time. You need a good
streamer going to lure a down leader.
But a ball can still stream if the potential cranks up
high enough, and the resulting strike can often be a
a stout one if it can overcome the poor streaming
of the smooth ball.
Both masts should be well grounded.
It's not an accident that most lightning rods have
a sharp point, the same way as most flag poles
have a round ball on top.
One is designed to stream as well as possible in
order to become a more likely target than what it
protects, and the other is designed to stream poorly
to resist strikes compared to the other better streaming
objects near it.
No streamer, no cloud to ground lightning at that
point on the earth. BTW, I've got pictures of streamers.
You can see them at night, and they bend and point to
the down leader as it approaches the earth.
The first one it can connect to forms the final path to
ground, and I think this is in the last 150 yards or so
if I remember right. The leader traveling in appx 150
yard or so steps through the sky.