The house i recently moved into has 4 lightning rods on it (paranoid?). The two on the main roof have yellow globes in their middles, and are still fully intact. The other two, however, have white porcelin globes that are half gone - partially shattered. My question is, is the conductivity (or any other property) affected when these globes are damaged.

And, also, any additional thoughts/experiances with lightning rods would be appreciated

-- Chris Hackbardt (chackbardt@industrialvac.com), January 21, 2002

Answers

4 lightning rods is not really unusual / uncommon. If the shattered globes are really porcelain, they served a decorative function only. Metal globes also serve as decorative ornaments, but in addition serve as "charge concentrators" so if a high energy burst of lightning were to strike that point in the lightning rod "system" the tip of the lightning rod would not be vaporized / damaged. (This is what may have actually happened to the porcelain globes -- if they are in fact porcelain. Or, someone may have shot at them with a gun. It is unlikely they were damaged by hail, weather, etc.)

If this is an old system, someone probably knew something you don't today. Lightning does strike in the same place twice, three times. four times, etc. It is probably worth further investigation to check the integrity of the system.

You can check the integrity of the system yourself by making sure that you physically have good, tight, connections between each of the rods, the connecting wire is unbroken, and that the connecting wire does in fact run from the rods down into the earth. Also check the earthing connection --- make sure that the connection point is not corroded. Don't waste your time (or money) in taking any ohmic readings. They are of little value and can really only be changed or improved with a great deal of effort and sometimes a great deal of money. (After all, they have lightning rod systems in the Saudi desert --- and they earth is sand!)

-- Ken in NY (cjpopeck@worldnet.att.net), January 21, 2002.

If you want to replace the two round balls they are available from Van Dyke's Restorers at 800-558-1234 or www.vandykes.com for $34.95 plus S&H each.

-- Ken S. in WC TN (scharabo@aol.com), January 22, 2002.