Benjamin Franklin was attracted to electricity. Given its similar color, crackle, and configuration, he suspected that lightning itself was electricity. Noting that a pointed metal needle could draw electricity from a charged metal sphere, Franklin became convinced that a metal rod could coax lightning from the sky. Why? So it would strike the rod instead of buildings or passersby.
As legend has it, Franklin hopped on a horse in 1752 with key-adorned kite in hand, determined to prove his conviction. The two pranced about under stormy skies until the charged-filled atmosphere energized the key and confirmed his suspicions.
More than two-and-a-half centuries later, lighting rods persist—as decorative architectural pieces, as vestiges of the past, and as mitigators of lightning’s power.
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Franklin later extended his lightning-rod idea to ships, including British warships, which were eventually outfitted with anchor chains that stretched from the top of their wooden masts to the sea. They aimed to dissipate electrical energy so the masts would stay intact if lightning struck. Soon, lightning rods were widely adopted in the northeastern United States, and elsewhere during the mid-1700s.
But not without resistance from some quarters, including the clergy. In fact, the Reverend Thomas Prince, pastor of Boston’s Old South Church, asserted that the Cape Ann earthquake of 1755 could be attributed to the ubiquitous placement of lightning rods in New England, especially in Boston. Centered off the coast of what’s now Massachusetts, the earthquake, Reverend Prince seemed to imply, was no accident given man’s unwise attempts to deflect the hand of God.
Today, Franklin’s lightning rods are known by many names: air terminals, finials, lightning conductors, or strike-termination devices among them. To me, calling them strike-termination devices makes it sound as if once a lightning bolt strikes the rods, the danger is averted. Instead, the rods, typically a half-inch in diameter, are connected to a metal cable hidden within the building or structure. The diameter of both the rod and cable vary depending on the height of the building and the type of metal. In general, the higher the building, the heavier the rods and cables. No matter the size, the cables make their way down to Earth, where they are anchored. Grounded, the lightning rod dissipates the lightning strike’s energy.
Without this seemingly simple system, damage to a structure can range from a minor insult to a complete loss. Parker M. Willard Jr. has seen just that. “We see a lot of damage from indirect strikes that come in through the utility lines,” he says. “The average insurance claim is $7,400, and I’ve seen some in excess of $700,000.”
Willard is the co-owner of Boston Lightning Rod Company, along with his father, Parker M. Willard Sr. Willard Jr.’s great-great-grandfather, Henry Willard, founded the company, which is based in Dedham, Massachusetts, 144 years ago. Now 40, Willard Jr. started working for Boston Lightning Rod when he was 16. The lighting-rod industry is “family oriented,” according to Willard. Multigenerational, really. “We’re one of the oldest [lightning rod companies] in the United States,” he tells me. “It’s not unusual to go to trade seminars and meet the next generation. There are a lot of lightning-protection families out there.”
When it comes to lightning and its stupendous energy, the bottom line, says Willard, is that lighting rods, when installed correctly, provide an effective path to ground for electrical energy, thus mitigating or avoiding damage to buildings. Especially when surge protection for incoming telecommunications, electric lines, and the internet is added to the setup.
“A lot of times people will put lightning rods up on their home or business and think they’re protected, but the structure can take an indirect strike to a utility line or a transformer outside the structure and the lightning rod is defenseless against that kind of strike,” Willard says. That’s why surge protection for telecommunications and cable have become a bigger and bigger part of his business: “Twenty years ago, people had a telephone, a TV, and an electrical line. Now they have high-end electronics, stuff that’s highly susceptible to any kind of electrical surge. A lightning rod system protects against a direct strike. Surge protection protects against an indirect strike.”
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In fact, most structures need more than one lighting rod, Willard explains. The rods should be spaced across the structure’s main ridge, with a maximum distance of 20 feet between them. The average house needs three or four rods, and ideally other rods should be placed on prominent points such as chimneys and dormers. All are interconnected with that all-important cable that runs to ground.
“The idea is that when lightning strikes your house, or any building, you want it to strike in a safe place that takes the current down to the ground without damaging your house, your television set, or you,” says Joseph Dwyer, a professor of physics at the University of New Hampshire. “You can’t prevent the lightning from striking, but if it’s going to strike a certain area, it gives it a safe place to do it.”
In the past, people favored what are known as Franklin air terminals—rods that come to a point at the top. Willard says that until recently they were used almost exclusively in the United States, because their points were believed to conduct electricity more effectively. Now, most newly installed lightning-protection systems use blunt, or rounded, rods. Studies have shown that blunt terminals work just as well as their pointy brethren, if not better. Plus, they’re safer to install—no risk of impalement.
“Safety is always a concern, and you can’t be afraid of heights in our business,” Willard says. He and his crew have worked on some of the tallest buildings in Boston, including the landmark Prudential tower in the heart of the city. Lightning rods or no, Dwyer says humans should have a healthy fear of lightning, especially when outside. “There’s no safe place outside during a thunderstorm,” he says.
That’s because most lightning never leaves the storm. Often, it never strikes the ground, traveling upward and branching out a bit in the sky. It’s the lightning that travels down toward the Earth—cloud-to-ground lightning, as it’s called—that can threaten life and property. “If you ever see a nasty-looking cloud up there, you might think, ‘I’m okay, maybe there’s no lighting,’” says Dwyer. “But it could be that that storm has been making lightning for a while. It just hasn’t bothered to send one down to the ground. The lightning you see first may be just the tip of the iceberg.”
Dwyer describes lightning as “a really big spark that is measured on the scale of miles or kilometers and is about as wide as a human finger.” It can travel 100 miles through a storm by breaking down the air in front of it and transferring charges.
What’s more, lightning doesn’t travel in a smooth line; it zigzags. “It will go maybe 50 yards, and then pause as if it has run out of steam, then it will suddenly leap forward another 50 yards, sometimes in a new direction, sometimes it will branch,” Dwyer says.
Lightning is erratic, so people try to impose order—even if that order leads to more disorder in the form of myths. As it happens, lightning does strike in the same place twice—and sometimes more. Take the Empire State Building, for instance. The New York City art-deco landmark is struck nearly 100 times a year.
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Some people think that lightning rods actively draw lighting. That, too, is a myth; they help dissipate electrical energy if it forms. But get this: Lightning rods did attract attention from European fashionistas in the late 18th century. According to the Lubbock Morning Avalanche’s May 13, 1933, edition, ladies of the haute mode were wearing lightning rods attached to their hats, hats known as chapeau paratonnerre. The so-called rods, the paper said, “consisted of a woven metal ribbon which encircled the hat and terminated in a long silver cord trailing on the ground.”
Because they are so prominent, real lighting rods have also inspired decoration. I appreciate good design, so I decided to search for lighting rods with fine form. I came across some striking designs: an antique copper lightning rod with a starburst tip, a vintage lightning rod with a wind indicator from Maryville, Missouri, and a vintage lightning rod in ornate hammered aluminum with a cobalt-blue ball and a roof mount. Prices ranged from $49.99 to $145.
All lovely, but it was the cobalt-blue ball that caught my eye. To my disappointment, it was made from hard plastic, not glass. Some people say glass balls were added to lightning rods so people would know if a structure had been hit should they find the ball shattered following a storm. Others say this is not so. No matter, the glass ball has become a decorative feature.
According to Willard, nowadays the glass balls are purely ornamental. He sees them on old barns in Maine, New Hampshire, and Massachusetts. “They don’t explode, and they don’t glow,” he says. “Lightning passes harmlessly right through them. They’ve returned over the years because some people want them as an architectural point.”
I asked Willard if he has installed lightning rods on his home. “That’s only a recent development,” he confided. “I was just doing the siding and the roof on my house before I put the lightning rods on.” After a roofing job, homeowners need to have someone qualified reinstall the lightning rods. They may look simple to install to the untrained eye, but they have idiosyncrasies, and if installed incorrectly they can be dangerous.
That’s why I’ve decided to purchase a single lightning rod, a dramatic one, and install it in my living room, so I can enjoy its sculptural qualities absent the storms. I suspect it will make for a striking piece of art.
This post appears courtesy of Object Lessons.
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