Maybe it was the sting of having a coworker peer at him intently and ask, "Where you come from? You a foreigner?" when he tried to express himself that made Jim Arnold yearn to finish his education.

Or maybe it was delayed response to his mother's hickory switch-cumaid to education, or his quest with a vengeance to prove his ability to detractors.

Whatever, his reason, Jim Henry Arnold earned his BA degree from the University of the District of Columbia Saturday and, along with it, the usual blushing graduate's share of pomp and circumstances, hot sun and long speeches. So what if he's 76 years old?

Arnold, the oldest of the approximately 1,200 members of UDC's class of 1981, and a rarity even at a school where the average student is 28, finished his educational odyssey after a 10-year effort, beginning at the old Federal City College. He received his high school diploma from the Anacostia Adult Education Center in June 1971, almost 35 years after he finished junior high school.

An honors student, Arnold was unwittingly recruited by the ROTC ("Dear Sophomore, it's later than you think!. . . You are nearing the end of your eligibility for receiving an Air Force Commission at the baccalaureate level," and the letter), invited to join the National Deans' List and feted along with other honors students at a university dinner last April. Not bad for a man who finished junior high school at 33.

"I didn't know there was a verb in the English language until I was 30 years old," Arnold said, revealing just a little of his healthy sense of self-appreciation, and pointing up a difficulty for a man who married a teacher. His wife, Etta, now retired, taught at the District's Washington Vocational High School.

UDC gave Arnold his first chance to attend school full time since he left trade school in his teens. Also, he acknowledges, his college studies gave him one of his few opportunities to be publicly proud of a black identity that sometimes lay hidden beneath a cream-colored skin.

Born in Greenwood, S.C., in 1904, in the days when "white men had two families," he says, Arnold was one of three sons of a black woman and a white man. "But I had nothing to do with it, and I have the right to take advantage of anything that's due me," he says with a slight defensive jut of the chin."It's the white man that messed everything up, not me."

At nine, he was big enough to work at odd jobs, he says, so he was taken our of day school to help support his mother and two brothers. A few years later he left Greenwood for vocational training in Philadelphia, where he learned "to read (building) plans before I learned to read writing." He also picked up several other trades, including drafting and carpentry, he explains, because his home town was so small that a specialist couldn't support a family there.

The experience served him well. He became so handy he built his own brick two-story Northeast Washington home for $20,000 in 1951. With the help of Etta and his only son Laurence (now 40, living in D.C. and the father of Patrick, 9, and Erica, 7), Arnold took a year off from his construction job and did all the work himself except the plumbing, electrical wiring and blueprints, which were drawn from his own designs.

His stories about picking up his various skills are endless. "When I first started laying bricks, I was about 17 years old," he says, launching into what is clearly a favorite among his catalog of anecdotes. "This other fella was already a bricklayer and he saw me laying these bricks and said, 'You better get you a tin cup and a guitar to make you a nickel; you'll never be a bricklayer.'

"Weeelll, I says, I'll make him eat those words,'" Arnold says now. "The next time he saw me laying bricks they were as smooth as marble. He got to be my buddy after that. And I," Arnold adds with pleasure, "got to be his supervisor."

His persistence would be his only comfort, especially when it became clear that racial descriminatin threatened to keep him out of construction work when he moved to the District in the 1930s. Union work paid $1.50 per hour to a non-union $1, but it was almost impossible for blacks to join the union.

On the advice of an in-law, he joined the bricklayers' union in 1937 by going to Charlottesville, Va., signing up and then transferring his membership to the District chapter. He never misrepresented himself, he says; he merely "passed for whatever they passed on to me. When they asked me if I was white or colored, I said, 'What does your vision tell you?'"

It was a crucial step that has made his career, though he was to be dogged by fear of the consequences of discovery and then dogged by the fear of selling out his race. It was a delicate tightrope that Arnold learned to walk.

When he was trying to buy a house in Philadelphia during the World War II years, where he moved his family while he worked in the Navy Yard, his Realtor tried to abrogate the deal when he discovered Arnold's racial identity. Arnold took him to court and won the right to buy. And when he left Philadelphia to move back to the District, "I turned around and sold it to the blackest woman I could find," he said, "so there would be no mistaken identity.

"Etta would say, 'You better let those white people alone. They aren't going to let you do anything.' Well, that just worked my feathers," said Arnold. "I always done something better when somebody told me I couldn't."

He was to become familiar with the insides of lawyers' offices in the coming years. He moved back to D.C. after the war and worked for several lucrative years until 1957, when someone revealed his race to an employer.

For the next 10 years until his retirement, Arnold says he began to suffer from the same tricks he had watched played against other blacks for years: information relayed clandestinely to whites so they would know where the new jobs were; repeated transfers to almost-completed sites to keep blacks perpetually out of work.

Determined to fight the treatment, Arnold began a letter writing campaign that included then-vice president Lyndon Johnson, former attorney general Robert F. Kennedy and the head of the Fair Employment Practices Commission. He continued the campaign until he retired in 1967.

Now that he's retired, Arnold lets it all hang out.

"Young people today don't realize how close they are to slavery, ever since Nixon got in and messed the whole thing up. People don't realize that they're being resegregated, only this time it's the segregation of the dollar," Arnold says, discoursing on one of his newly favorite topics. "If you pay $100 a night for a hotel room, you can't get a good night's sleep. You'd keep waking up, wondering, 'How am I going to pay for this hotel room?'"

These days he is particularly concerned about fellow students, who, he suspects, fail to appreciate their opportunities and try to substitute shortcuts for hard work. He has been known to admonish cheaters with a loud, "You'd better put that paper down. In real life, every encounter is a final exam."

His devotion is returned by students and faculty alike. "He's an inspiration," said Prof. Joseph Drew, one of Arnold's instructors in his political science major. "There is no better feeling than to have a student so motivated. We'll all miss him."

And now? Anold says he's thinking of going to law school.