When the Chatham Volunteer Fire Department was strapped for cash to buy a new fire truck and safety equipment last year, the Marline Uranium Corp. was only too happy to come to the rescue.

Within days after the town launched its fund-raising drive, executives of the New York-based energy firm hand-delivered a $2,700 check to Landon Worsham, the fire chief. The firm later came through with another $500 from its subcontractors.

"We were really impressed," said Worsham, who owns an appliance store on Main Street. "It proves that they want to do what's right."

Marline's delivery of the check, a ceremony that was dutifully covered in Chatham's weekly newspaper, was only one facet of a sophisticated public relations campaign that has largely sold Worsham and hundreds of others in this tiny tobacco-growing community on the virtues of uranium mining in their backyards.

The success of this courtship was underscored Wednesday when, after three-years of exploratory drilling, Marline announced it had hit pay dirt--a reputed 30 million pound discovery of high-grade uranium ore, lying beneath a few farms off an isolated dirt road 25 miles north of the North Carolina border.

In central Virginia counties, where Marline also has been exploring, the prospect of uranium mining and milling has conjured up fears of contaminated water supplies, radioactive mill tailings and other environmental disasters. Not so in Chatham, the seat of stoutly conservative Pittsylvania County. About 50 of the town fathers who had gathered at the local community center broke into spontaneous applause after they heard Marline's announcement.

"It's incredible," said Joanne Spangler, a chemist from nearby Danville and one of Marline's few local critics. "This is the first time Yankees have come into southern Virginia and been welcomed with open arms."

It is a welcome, moreover, that could have implications for the rest of Virginia. Marline and its environmental foes are preparing to square off in the state legislature over the state's recently imposed moratorium on uranium mining that will expire in July, 1983.

In today's depressed uranium market, jolted by the slump in nuclear power demand, there is no guarantee that the Marline find will ever be developed.

Nonetheless, the chairman of the Coal and Energy Commission's uranium subcommittee, state Sen. Daniel Bird (D-Wytheville), has predicted that his panel will recommend next month that the state mining ban be lifted for Pittsylvania County, largely because of the backing Marline has garnered from local residents.

Environmental activists and some Northern Virginia officials, such as Fairfax County Board Chairman John F. Herrity, see this as "the foot in the door"--a step that could eventually lead to mining operations as far north as Fauquier and Culpeper counties on the fringes of the Washington suburbs. Nor do the critics take any comfort from the enthusiasm of Pittsylvania County's citizenry.

"They've been sold on this," said Spangler, who has formed a group to oppose Marline. "The people don't understand the technical hazards of uranium mining. It's like what they did in Hopewell. The people there were very happy to have Allied Chemical in there, but now because of contamination from the pesticide Kepone the James River is ruined for fishing for years to come."

The wooing of Chatham is indeed a textbook lesson in corporate public relations, a study of how entrepreneurs, armed with millions of dollars and the right political connections, managed to win over a rural populace in the heart of Southside Virginia.

Marline has estimated that it has already spent about $20 million in Virginia--a sum that includes leasing, exploration, lawyers, consultants, a pollster, public relations and lobbyists. "But it's not the money," said Norman W. Reynolds, a vice president of Marline. "It's people. We've been up front, we haven't hidden anything, we've told them what we were doing."

The boomtown excitement that has infected Chatham is no deep mystery. Established as the county seat 205 years ago, Chatham is a quiet town of 1,550 people with no movie theaters or liquor stores and only one thoroughfare.

And in this area, where there has been much talk lately of threats to the federal tobacco program and layoffs at the nearby Dan River Fabrics plant, Marline has made big promises--a $200 million mining and milling operation that would provide 900 new jobs and generate about $1.2 million in new tax revenue for county coffers.

"You have to remember, we're still basically tied to the old South economy, which is cotton mills and agriculture," said state Del. Charles R. Hawkins (R-Chatham). "This . . . can be a tremendous boost."

But there has been much more to Marline's sales pitch than the promise of jobs and bulging tax coffers. The company, a subsidiary of the Marline Oil Corp., an oil and gas exploration firm with fewer than 50 employes, moved into the area in 1977, sending around teams of lawyers and geologists to lease the mineral rights from local landholders.

In the years since, Marline has leased about 40,000 acres in the area, luring hundreds of landowners, including some of the county's most prominent citizens. One of the first to sign was Edwin R. Shields, a member of the Pittsylvania County Board of Supervisors and, until recently, the board's chairman.

When company lawyers first approached the supervisor and his two brothers with a lease about three years ago, "I didn't know what uranium was," said Shields, a slow-talking tobacco farmer.

Shields and his brothers finally agreed to lease away the rights to their 367-acre farm anyway. "We knew there was a possibility of getting some money out of it," he said. "That's always in the back of your minds."

By last year, Shields had resolved whatever questions he may have had about uranium. Appearing at a state hearing in Richmond, the then county board chairman delivered a short speech endorsing mining in Pittsylvania and praising Marline officials as "honest and well-intentioned men."

The speech was mostly written for Shields by Marline officials, a company spokesman later said. "They may have written a few things," said Shields when asked about it, but added he didn't see any conflict of interest. "If there's a health hazard involved, I'm opposed to it," he says. "But they say they can control it so there won't be any health hazard."

Another who early on signed up with Marline is Preston Moses, editor of the Chatham Star-Tribune, the largest circulation paper in the county. He leased 249 acres to Marline in November 1978.

Moses, who sees uranium mining as an economic blessing, has also been an unabashed booster of Marline, both in his weekly "Rambling Around" column and in his news stories. Not surprisingly, Marline's long-awaited announcement last week was timed to coincide with the Star-Tribune's weekly deadline.

"I think the Star-Tribune has had an effect in alleviating the fear that people had," said Moses. "I've accentuated the positive side."

Marline has taken other steps to tell its story. It hired the assistant county administrator to help manage its landleasing program. With the aid of the Washington public relations firm of Robert N. Pyle, it began distributing a newsletter called "Marline News," complete with feature articles like "Exploration--A Safe Process."

And last November, it sponsored a "Uranium Fair" at a local school. There were exhibits on uranium mining, a bluegrass band to entertain, Brunswick stew and Fred Flintstone movies on the wonders of nuclear power.

While Marline was putting on the hard sell, the small band of local critics was having its own problems. After Spangler's group called a public meeting last fall, its members were chagrined to find in their midst Dorothy Blitz, the spunky 36-year-old Martinsville woman who has gained national notoriety for her membership in the Communist Workers Party and fight for federal job training benefits. The uranium foes have yet to live that one down.

"The Danville paper . . . played up this great big article about this Communist who was opposed to uranium mining," said Spangler. "They didn't have to say any more."

The man behind Marline's extraordinary effort here--Reynolds--celebrated the uranium announcement by hosting a catered affair at his lavish new home with swimming pool a few miles south of here. Shields was there, as was editor Moses, Dan Sleeper, the county administrator, and dozens of others.

". . . Some of the people that have opposed us . . . they'd be opposed to any new industry," Reynolds said. "But the people here have taken the time to listen."