Honolulu Star-Advertiser © Susan Scott
July 4, 2008
While paging through a book of sea stories recently, I found some legends about St. Elmo’s fire, one of nature’s best fireworks shows.
Is this glimmering on one’s boat benign or dangerous? I wondered. What should I do if I see it on mine?
Ancient sailors gave this normal meteorological event mystical meaning. Depending on which country mariners hailed from, the ghostly glow was a good omen (Europe) or a bad omen (China).
Many sailors gave significance to the up or down movement of the radiance. Some believed it to be the unsaved souls of drowned sailors asking for prayers, and others thought it was an angel come to save the ship.
To some mariners the odd light predicted a storm’s passing. To others it told of a storm approaching. You name it and sailors of old made it up.
Elmo, short for Erasmus, was a Sicilian bishop who lived around A.D. 300. After becoming mortally ill during a storm at sea, one story goes, Elmo promised the sailors that after he died, he would appear to them if their ship was going to be saved.
Soon after, a light appeared at the mastheads, the men survived and St. Elmo became the patron saint of sailors.
St. Elmo’s fire was famous. The ancient Greeks noted this radiance, as did Magellan, Columbus and Darwin. In “The Tempest” Shakespeare says the fire “flamed amazement,” and Melville in “Moby Dick” wrote, “God’s burning finger has been laid upon the ship.”
“A famous American figured out the cause of this flickering flame, which also occurred on church spires and weather vanes. In his 1749 notes about the lightning rod, Ben Franklin correctly described St. Elmo’s fire as atmospheric electricity.
Today scientists call the occurrence a corona, a point discharge or a corposant, from the old Spanish “corpo santo,” meaning “saint’s body.”
“One weather expert thinks the burning bush Bible story may have been a point of discharge. Another theory suggests a corposant issued the spark that caused the Hindenburg Zeppelin disaster.
I’ve never seen this electric glimmer, but people describe it as a dancing flame or small fireworks. It occurs on pointed, grounded objects and can last for minutes. The bluish-white light hisses but doesn’t feel hot, nor does it burn objects.
The phenomenon has to do with charged air particles.
In fair weather the atmosphere’s electric field potential is 1 volt per centimeter. St. Elmo’s fire occurs when the electrical potential reaches 1,000 volts per centimeter near a pointed object. Ten-thousand volts per centimeter creates a lightning bolt. These electrical conditions occur during thunderstorms and sometimes during tornados.
Wondering what to do if St. Elmo strikes my boat, I read some modern sailors’ accounts of their experiences. Several mentioned their arm hairs standing on end, and feeling tingling in the scalp, but otherwise, the current shimmering on the mast and down the shrouds did no harm.
Electricity running loose on your boat, though, is spooky. One sailor wrote, “There’s something almost supernatural about this natural event.”
“Now I know what to do if a corposant visits my boat: Like tonight, I will sit back and enjoy the fireworks.