Fighting the Dark Clouds of Doubt : Weather: Keith Brown and other professional cloud-seeders have to work hard to clear the air of myths about what they do.

The Mayans threw middle-age women into wells to appease their rain god. The English of the 1700s sent bell ringers into church towers, hypothesizing that loud noises shook moisture from the clouds. The practice was banned after lightning killed too many bell ringers.

Keith Brown cringes when reminded of such history. As a modern cloud-seeder, he is paid good money to increase rain and snowfall in places around the world, including Los Angeles.

Although the work is decidedly high-tech, Brown and other cloud-seeders are haunted by ancient Mayans and a more recent image of the rainmaker as traveling charlatan. “We are perpetually trying to avoid the stigma of that image,” said Brown, president of North American Weather Consultants, a Utah-based company. “We don’t even like the name rainmaker .”

And there’s one more problem: Science has yet to confirm that cloud-seeding actually works.

The process recently came under public scrutiny because of North American’s six-month $181,460 contract with Los Angeles County. Like other California communities, Los Angeles has employed cloud-seeders at various times during the past 30 years. Last week, the Board of Supervisors--wondering why taxpayer money was being spent to encourage more rain in an already sopping winter--decided to put the contract on hold.

But seeding is expected to resume once the heavy storms pass, and officials did not so much as question the validity of cloud-seeding.

Theoretically, the industry-wide process of injecting silver iodide particles into clouds should help turn airborne moisture into precipitation. Cloud-seeders--who release these particles from airplanes and ground-based generators--insist they can coax as much as 15% more rain from storms that would have rained anyway.

A given storm, however, can deliver twice as much precipitation as predicted, so it’s difficult to tell how much of the extra rain is man-induced and how much is a natural variation. Also, no two storms are alike, making it difficult to scientifically duplicate results.

Researchers, deprived of these measurements, can’t give their stamp of approval.

“Those commercial operators have evidence that they consider conclusive,” said Gabor Vali, a professor of atmospheric sciences at the University of Wyoming. “Other people consider it marginally acceptable or not acceptable all. It all comes down to what you’re willing to believe.”

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Brown and other cloud-seeders tend to go about their business quietly because they know they are tainted by a colorful history.

In his 1992 guide, “The Weather Book,” Jack Williams provides several early accounts of rain-making in America:

* A New Yorker by the name of G. H. Bell suggested in 1880 that gusts of air could be blown out the top of a 1,500-foot tower, causing updrafts that would create rain clouds.

* An 1893 Boston Globe article offered a more earthy approach. The writer stated that one soldier, fighting for 12 hours, perspired six gallons of sweat. Multiply that by 1,000 soldiers and you had enough moisture to bring a storm.

* About the same time, patent attorney Robert Dyrenforth garnered $10,000 from Congress to launch ammunition-laden balloons over Texas. The resulting explosions created a racket, but no rain.

But the most famous, or infamous, of America’s rainmakers came from Glendale.

Charles Hatfield earned his reputation in 1916, when San Diego officials agreed to pay him $10,000 to bring relief to their drought-stricken city. Hatfield erected towers near a reservoir and, using a “secret” chemical formula, began triggering explosions.

Five days later, it rained. And it kept raining--11 inches in all. The reservoir flooded. Houses were destroyed. Residents sued the city for $3.5 million and municipal officials subsequently refused to pay Hatfield.

According to newspaper accounts, he later popped up at a succession of Southern California communities. A Times article from Dec. 21, 1924, reports: “Charles Hatfield, the rainmaker of Glendale, failed to get proper cooperation from Jupiter Pluvius Friday when he invoked the weeping clouds for the ranchers of Kern County. As a result, he is out $2,000. The ranchers had agreed to pay Hatfield this sum if he brought them 1.23 inches of rain by midnight Friday. The rain came but it wasn’t enough by approximately .36 of an inch. So Hatfield wrecked his rain-making paraphernalia and has departed for other fields.”

Scientists now suspect that the rainmaker’s successes were merely natural storms. Years later, he was portrayed as nothing more than a slick-talking shucker--the Burt Lancaster character, Starbuck, in a 1956 film, “The Rainmaker.”

But the San Diego flood ensured Hatfield a place in rainmaking history. And it probably ensured generations of doubters to follow.

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Modern cloud-seeders stumbled into respectability in the mid-1940s. Vincent Schaefer, a General Electric scientist, was trying to determine why icy wings interfere with airplane radio signals. Loading a block of dry ice into an ice box, Schaefer noticed that his breath created a cloud of ice crystals, which are the starting point for rain and snow.

Schaefer took to the skies, dispersing dry ice from an airplane in vaguely the same manner that modern seeders work. Bernard Vonnegut, a colleague and brother of novelist Kurt Vonnegut, discovered that silver iodide was better suited for creating ice crystals. Cloud-seeding, as it now exists, was born.

In the years since, researchers have struggled to confirm this theory on a scale larger than Schaefer’s ice box. In 1959, clouds were systematically seeded over Missouri. “I’m convinced we decreased the rainfall,” said Roscoe Braham, a noted researcher who was part of that study. Experiments at Colorado State University produced promising results but fell short of conclusive evidence. Same with a Florida program in the 1980s.

A 12-year Israeli project stands as the sole successful effort to confirm the technology. But skeptics--again citing the variability of storms--contend it proved only that cloud-seeding worked at one specific location during one specific project.

And a sharp decline in research means the technology may not be confirmed or disproved for some time, Braham said.

So how have cloud-seeders survived such doubts? How has North American garnered contracts in Greece and Guatemala and four Western states?

First and foremost, it’s because water remains among the Earth’s most precious commodities. Southern Californians, especially, seem willing to try anything to get more of it.

Cloud-seeding remains relatively cheap, as well. If North American is truly making good on its claims, then Los Angeles County is paying between $20 and $40 per acre-foot for the extra rain in its reservoirs. By contrast, the county pays more than $400 per acre-foot for the water it buys and brings from elsewhere.

“There’s some real basis to this,” said Mark Heggli, a meteorologist with the state’s Department of Water Resources. Heggli is involved with a current project to seed clouds in Northern California. “You have to look everywhere to meet the needs of the people. Every little bit helps.”

Skeptics, however, suggest that government agencies fund such work simply for appearance’ sake.

“Look at it from the politician’s viewpoint,” said Art Rangno of the University of Washington, whose 20 years of research have left him critical. “They’re not just sitting on the drought. They’re doing something. They’ve hired the best cloud-seeders money can buy.”

And when the government hands out money, a line quickly forms.

“When we were in the worst of our drought,” Heggli said, “I kept on getting people who had magic potions they wanted to sell to the state.”

One man arrived from Australia with huge cones that he set on mountaintops. Not only would these cones produce rain, the man insisted, but they would solve air pollution as well.

“Everyone had something magical that you put in your pocket or buried in the ground,” Heggli recalled. “And everyone guaranteed results.”

Brown chuckles when he hears such talk. He tries to ignore the loonies and replies to critics with a country sort of wisdom.

“It’s like fertilizing your field,” Brown said. “You can’t grow corn on cement. But if you have the field, you can fertilize and get a bigger crop out of it.”

“We do not,” he was careful to explain, “have any magic faucet in the sky.”

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Times researcher Julia Franco contributed to this article.