In message , Richard Clark
writes
By the same logic (and experience), charge will accumulate on the
surface at the smallest radius - hence the points on lightning rods.
By extension, this is also the source of capacitor failure at either
the edges (smallest radius of a plate) or in surface burrs.


Again scraping the very bottom of the memory banks, I seem to recall
that when lightning rods were first used (in the late 1700s), the
British used sharp points. The French, in the spirit of one-upmanship,
decided that theirs should have brass balls. DOH!!!
Ian.
--

"Ian Jackson" wrote
, Richard Clark writes
By the same logic (and experience), charge will accumulate on the
surface at the smallest radius - hence the points on lightning rods.
By extension, this is also the source of capacitor failure at either
the edges (smallest radius of a plate) or in surface burrs.


Again scraping the very bottom of the memory banks, I seem to recall
that when lightning rods were first used (in the late 1700s), the
British used sharp points. The French, in the spirit of one-upmanship,
decided that theirs should have brass balls. DOH!!!
Ian.
--

Very interesting! However the American Benjamin Franklin's pointed
lightning rods (it was not a British design) was never scientifically
challenged until a couple of years ago. Scientists have now shown that
blunt-tipped air terminals are attached by lightning with significantly
higher frequency than sharp tipped rods are. Pretty amazing that it took
over 230 years to "discover" this! So scrap the concept that a sharp edge
attracts charges, at least it does not attract lighting, the ultimate
charge.

http://www.usatoday.com/weather/reso...-rod-tests.htm
http://www.esdjournal.com/articles/f...n/franklin.htm
http://www.mikeholt.com/news/archive...tningblunt.htm
etc, etc

Jack Painter
Virginia Beach VA

There is more to the Franklin rods used in England: George III is said to
have required the ends to be converted to round from pointed when the
Revolution started - a pointed slam at Dr. Franklin. Nevertheless, the
houses (once there were two) of parliament were protected by Dr. Franklin's
rods.

It would have been so easy for the English to have co-opted Dr. Franklin
and quite changed the course of history. Instead, he conned the French out
of the critical support needed to win our freedom. 73 Mac N8TT

--
J. Mc Laughlin; Michigan U.S.A.
Home:



Very interesting! However the American Benjamin Franklin's pointed
lightning rods (it was not a British design) was never scientifically
challenged until a couple of years ago. Scientists have now shown that
blunt-tipped air terminals are attached by lightning with significantly
higher frequency than sharp tipped rods are. Pretty amazing that it took
over 230 years to "discover" this! So scrap the concept that a sharp edge
attracts charges, at least it does not attract lighting, the ultimate
charge.


http://www.usatoday.com/weather/reso...ghtn-rod-tests
..htm
http://www.esdjournal.com/articles/f...n/franklin.htm
http://www.mikeholt.com/news/archive...tningblunt.htm
etc, etc

Jack Painter
Virginia Beach VA

In message , J. Mc Laughlin
writes
There is more to the Franklin rods used in England: George III is said to
have required the ends to be converted to round from pointed when the
Revolution started - a pointed slam at Dr. Franklin. Nevertheless, the
houses (once there were two) of parliament were protected by Dr. Franklin's
rods.

It would have been so easy for the English to have co-opted Dr. Franklin
and quite changed the course of history. Instead, he conned the French out
of the critical support needed to win our freedom. 73 Mac N8TT

--
J. Mc Laughlin; Michigan U.S.A.
Home:



Very interesting! However the American Benjamin Franklin's pointed
lightning rods (it was not a British design) was never scientifically
challenged until a couple of years ago. Scientists have now shown that
blunt-tipped air terminals are attached by lightning with significantly
higher frequency than sharp tipped rods are. Pretty amazing that it took
over 230 years to "discover" this! So scrap the concept that a sharp edge
attracts charges, at least it does not attract lighting, the ultimate
charge.


http://www.usatoday.com/weather/reso...ghtn-rod-tests
.htm
http://www.esdjournal.com/articles/f...n/franklin.htm
http://www.mikeholt.com/news/archive...tningblunt.htm
etc, etc

Jack Painter
Virginia Beach VA




In message , J. Mc Laughlin
writes
There is more to the Franklin rods used in England: George III is said to
have required the ends to be converted to round from pointed when the
Revolution started - a pointed slam at Dr. Franklin. Nevertheless, the
houses (once there were two) of parliament were protected by Dr. Franklin's
rods.

It would have been so easy for the English to have co-opted Dr. Franklin
and quite changed the course of history. Instead, he conned the French out
of the critical support needed to win our freedom. 73 Mac N8TT

--
J. Mc Laughlin; Michigan U.S.A.
Home:



'Protected' is the word. What is not always appreciated is that the
primary purpose of lightning rods (usually called 'lightning conductors'
in the UK) is to PREVENT a strike by allowing the electrical charge to
leak away before sufficient voltage builds up to cause an actual strike.
Ian.
--

"Ian Jackson" wrote
'Protected' is the word. What is not always appreciated is that the
primary purpose of lightning rods (usually called 'lightning conductors'
in the UK) is to PREVENT a strike by allowing the electrical charge to
leak away before sufficient voltage builds up to cause an actual strike.
Ian.

Hi Ian, while Franklin originally thought this was the case, he and others
soon realized that safe handling of a lightning attachment was the function
of his Franklin Rods, NOT avoidance of attachment. There has never been any
proof that any device can prevent a strike from attaching to a particular
point. The controversy surrounding the CTS (Charge Transfer System) and ESE
(Early Streamer Emitters) exposes some of the dumbest junk science ever to
hit the lightning-rod snake-oil trail. It has been thoroughly discredited as
having absolutely zero effectiveness as a preventer and limited usefulness
as a standard Franklin Rod when installed as its snake-oil purveyors
proscribe. So please never assume that any rod, termination device,
voodoo-doll on the roof or anything else can have any affect whatsoever of
preventing a strike from attaching at any particular point.

Jack Painter
Virginia Beach, Virginia

In message QkAAd.35660$7p.12710@lakeread02, Jack Painter
writes

"Ian Jackson" wrote
'Protected' is the word. What is not always appreciated is that the
primary purpose of lightning rods (usually called 'lightning conductors'
in the UK) is to PREVENT a strike by allowing the electrical charge to
leak away before sufficient voltage builds up to cause an actual strike.
Ian.

Hi Ian, while Franklin originally thought this was the case, he and others
soon realized that safe handling of a lightning attachment was the function
of his Franklin Rods, NOT avoidance of attachment. There has never been any
proof that any device can prevent a strike from attaching to a particular
point. The controversy surrounding the CTS (Charge Transfer System) and ESE
(Early Streamer Emitters) exposes some of the dumbest junk science ever to
hit the lightning-rod snake-oil trail. It has been thoroughly discredited as
having absolutely zero effectiveness as a preventer and limited usefulness
as a standard Franklin Rod when installed as its snake-oil purveyors
proscribe. So please never assume that any rod, termination device,
voodoo-doll on the roof or anything else can have any affect whatsoever of
preventing a strike from attaching at any particular point.

Jack Painter
Virginia Beach, Virginia



As I said, I WAS scraping the very bottoms of the memory banks (and
licking them clean as well).....
Ian.
--

Wasn't Franklin that lunatic who used to walk around flying kites in the
middle of thunderstorms? And he now gets praised for it!

On Tue, 28 Dec 2004 18:56:13 -0500, "Jack Painter"
wrote:


"Ian Jackson" wrote
, Richard Clark writes
By the same logic (and experience), charge will accumulate on the
surface at the smallest radius - hence the points on lightning rods.
By extension, this is also the source of capacitor failure at either
the edges (smallest radius of a plate) or in surface burrs.


Again scraping the very bottom of the memory banks, I seem to recall
that when lightning rods were first used (in the late 1700s), the
British used sharp points. The French, in the spirit of one-upmanship,
decided that theirs should have brass balls. DOH!!!
Ian.
--

Very interesting! However the American Benjamin Franklin's pointed
lightning rods (it was not a British design) was never scientifically
challenged until a couple of years ago. Scientists have now shown that
blunt-tipped air terminals are attached by lightning with significantly
higher frequency than sharp tipped rods are. Pretty amazing that it took
over 230 years to "discover" this! So scrap the concept that a sharp edge
attracts charges, at least it does not attract lighting, the ultimate
charge.

http://www.usatoday.com/weather/reso...-rod-tests.htm
http://www.esdjournal.com/articles/f...n/franklin.htm
http://www.mikeholt.com/news/archive...tningblunt.htm
etc, etc

Jack Painter
Virginia Beach VA


Jack,

All three references are of the same article. Note the rebuttals at
the end of one of them.

I would also find it hard to believe that ANY rods on a 12000 foot
mountain were not hit in 7 years!

That study would suggest that pointed rods were excellent lightning
repellers and would protect things from being struck. Exactly what
Franklin first thought.

If not excellent repellers then it would be highly suspect of the
placement of the pointed rods on the mountain.

73
Gary K4FMX

Gary, K4FMX wrote:
"I would find it hard to believe that ANY rods on a 12,000 foot mountain
were not hit in seven years."

I saw a PBS program tonight on people scaling the highest peak in
Antarctica. It may never have been struck by lightning in modern times.
I spent two six-month hitches for my company on Tierra del Fuego. Not
quite Antarctica, but still so cold that lightnning is unknown on the
island.

Best regards, Richard Harrison, KB5WZI

"Gary Schafer" wrote
Jack,

All three references are of the same article. Note the rebuttals at
the end of one of them.

I would also find it hard to believe that ANY rods on a 12000 foot
mountain were not hit in 7 years!

That study would suggest that pointed rods were excellent lightning
repellers and would protect things from being struck. Exactly what
Franklin first thought.

If not excellent repellers then it would be highly suspect of the
placement of the pointed rods on the mountain.

73
Gary K4FMX

Hi Gary, the study is of course much more detailed than the articles
describe, I'll see if I can find you a link or post the abstract here
anyway. But no, there is absolutely no such conclusion in that study (or any
other accepted work) that any device can prevent lightning from striking a
particular point by "draining off" charges.

73,
Jack