On paper, Brigadier Ruby Corbett retired from the Salvation Army 15 years ago, after more than three decades of service. In reality, the 73-year-old Corbett is still on active duty -- particularly at Christmas time.

From Thanksgiving through December, 60 hours a week and more, she mans the Salvation Army kettles in Prince George's Plaza. What's unusual, however, is that Corbett doesn't live anywhere near the Hyattsville mall. She lives in Ontario, Canada -- 500 miles away.

For Corbett, buying an airplane ticket from Ontario to Maryland has become a cherished holiday tradition. She's been making the trip for 10 years, since November 1971. She receives no pay for her efforts, just love and thanks.

"You may think it's a bit odd for me to travel this far from home each year," acknowledged Corbett as she collected donations. "But being a member of the Salvation Army means that I am obligated to go wherever there is spiritual or financial need. And here in Maryland that means my work is cut out for me."

Corbett first began her yuletide work at the urging of a fellow Salvationist who had roots in Prince George's County. Informed that county bell ringers were in short supply, she agreed to pinch-hit at the Plaza for one season only.

But, says Corbett, God had other plans in store.

"My husband Harold accompanied me and together we discovered a hidden poverty that exists in Prince George's County," she recalled. "Strangers came to us with stories of local parents unable to afford holiday toys for their children and old people unable to afford nutritious food.... We knew we had to return."

And return they did, until two years ago when Harold Corbett, an equally dedicated member of the Salvation Army, died in his sleep at 81. The Corbetts always had complemented one another. His kettle outside of Woodies was filled quickly because he could talk to almost any passerby. And her kettle outside of Hecht's filled just as quickly because of her ability to listen.

This season, Corbett was accompanied to the Plaza by her sister Margaret Rogers, also from Ontario. Rogers, although not a Salvationist, still dressed in one of Corbett's spare uniforms so she could watch over Prince George's kettles in style.

Her sister's presence is a great comfort, Corbett said, though she is keenly aware of Harold's absence.

"At first I thought it would be too painful to return to Hyattsville alone," Corbett said. "But thankfully I realized that Harold would expect nothing less of me than to carry on with our tradition. After all, I'm working for two now, so I know I'm needed."

According to Capt. John Carter, the commanding officer of Prince George's Salvationists, Corbett is indeed an indispensable worker. She's one of only 15 persons Carter can count on to work long and regular kettle shifts. And Corbett is the first to report in the morning and usually the last to leave.

Carter makes arrangements for Corbett to stay with a local family, always a fellow Salvationist. Although she usually stays in Maryland until New Year's Eve, this year she left a few days early for a holiday celebration with her family.

"She's not quite 5 foot tall but even so she's every inch a trooper," Carter said. "With Mrs. Corbett on our side, I know we're going to be able to help a tremendous number of of deserving people."

As of early this week, the P.G. chapter had collected between $60,000 and $70,000, with money still coming in. This year's goal was $80,000.

The money was used to provide free food, shoes and toys to more than 10,000 of the county's shut-ins and needy residents.

Aside from looking after the physical needs of county residents, Corbett also has spent the past decade befriending them. What one Plaza patron calls her "quiet sincerity" has won Corbett a curious mix of fans.

"In certain respects, my first day back on duty is like a homecoming. By now I can pick out countless faces in the Plaza crowds and I must know hundreds of people by name."

"Can you believe it? A good number of people even bring me Christmas presents. Five hundred miles is a short distance to travel for such friendship," Corbett said.

One Hyattsville mother of two has brought Corbett a Christmas gift for the past four years, ever since Corbett saw her children in the shopping center, guessed they were truants and talked them into returning to school. The mother, who asked not to be identified, said Corbett is "someone who is willing to give a stranger the shirt off her back."

Shirley Cooper, a divorced mother of three young children from Adelphi, is another of Corbett's local admirers. "Just after my divorce three years ago, I had the good fortune of discovering Mrs. Corbett. My own neighbors didn't care to listen to my problems, but to my surprise, Mrs. Corbett did. We talked together like longtime friends right in front of her kettle. That's kindness I'll never forget."

If Corbett is nonchalant about the distance she must travel to volunteer each year in Hyattsville, it is because her marriage and Salvation Army career have taken her far greater distances -- halfway around the world, in fact.

In 1930 Corbett began both chapters of her life 400 miles west of Bombay, India. She was the first in her family to join the Salvation Army, though Harold came from a large family of Salvationists.

"I met Harold as a young school girl in Ontario and before I knew what hit me I was in love with both him and the Salvation Army. When he got the urge to preach in India, I knew I had to follow," Corbett said.

Married in Bombay, they spent their honeymoon training as Indian missionaries.

Together they mastered three separate Indian dialects so that they could minister to homeless prostitutes, thieves and lepers. Together, too, they oversaw a home and school for 100 Indian orphans. Somehow they also found time to start their own family of three children, who are now grown and scattered throughout the United States.

For 11 years they went without a vacation, but Corbett insists they still were adequately compensated.

"I learned to pull teeth, to give enemas and to deliver babies. I learned that giving is receiving." That is a lesson that Corbett applied repeatedly.

"It's just this simple," she offered, when pressed about the number of years she could keep on giving. "The day I read in the Bible that man should retire from God's work, then that's the day I'll quit."