One of them took up painting, another music, a third read biographies and a fourth made hats. All of them studied revolution during their quarter-century in prison and that is what Puerto Rico's newly returned nationalist heroes hope to sow on this lush and crowded island.

Oscar Collazo, Irvin Flores, Rafael Cancel Miranda and Lolita Lebron spent the day visiting friends, churches, and graves of political mentors, and traveling together with supporters, waving flags at each stop. But the passions surrounding their return won't last forever. Already it is obvious that they are very different from one another. Their roles here remain uncertain.

Before he was jailed in 1950 for attempting to assassinate President Truman, Oscar Collazo had been a metal polisher in the New Rochelle factory. The news photos from the day he was arrested show a resigned-looking fellow of 37, a family man who said then and repeats today that he never intended anything more than a demonstration to call attention to Puerto Rico's problems.

He was known in his suburban New York neighborhood and certainly appears now at the age of 67, to be a kindly, peaceable man, everybody's grandfather. He is articulate and thoughtful about history and his role in it.

"I read biographies -- scientists, political pamphlets and books from other inmates who were free to receive them. Anything that has the words revolution or fight for freedom, that kind of literature, is kept from inmates that are politically conscious."

With an eighth-grade education, Collazo taught himself Portuguese and French at Leavenworth Prison in Kansas. His English is the best of the four. "If people don't find me too old, I might be able to work on translations," he said in an interview.

It was Collazo who took the microphone from an overwrought, 59-year-old Lolita Lebron at Tuesday's press conference at the United Nations, responding calmly to questions about violence that had infuriated her. Lebron had just given the public the first of the semi-coherent, emotional pronouncements that have poured from her ever since.

She was 34 when she shouted, "Viva Puerto Rico Libre." from the House visitors' gallery in 1954, leading three countrymen in a shooting attack that wounded five congressmen. Though she fired her pistol at the ceiling of the House, not the floor, a note in her purse said "I take responsible for all." She later said she had not expected to live through the day.

Instead she spent 25 years in an Alderson, W. Va., federal women's prison. There she scrubbed floors, cleaned rooms and made flowered hats for the women, copying designs from magazines.

Her cell was decorated with religious icons and an altar, and she repeatedly said she lived only to do God's will. Her two children died in Puerto Rico while she was jailed, but she will not speak of them now. Her family, she says is the people of Puerto Rico.

Lebron would not be interviewed by The Washington Post, saying the newspaper had slandered the nationalists by recalling the movement's roots, long renounced, with sympathizers of Mussolini in the 1930s. The movement today is firmly socialist.

Irvin Flores Rodriquez, 55, went 14 years without a single visitor -- plenty of undistracted time to read Marx and Lenin in prison. A former tailor and coffee picker, he was not sure of his family's address, nor they of his, when he stood to shoot from the House gallery and, under the strict prison rules of the time, he could have only family visitors. He, Collazo and Cancel-Miranda became close at Leavenworth, trading the forbidden political literature back and forth.

Flores, a quiet, monosyllabic man, taught himself to paint. He did five portraits of Che Guevara and sold them to fellow inmates. He painted the hero of the nationalist movement, Pedro Albizu Campos, and is proud that his brother was once offered $500 for the canvas. But he had little money for supplies and painting gave way to politics, which he says must be his future.

"There is only one nation that looks similar to what I want for Puerto Rico and that is Cuba," said Rafael Cancel-Miranda, jailed since 1954 for his part in the House shooting. He already was an active nationalist, living in a Brooklyn tenement when he was arrested, and not for the first time. He had refused to be drafted in 1949 and spent two years behind bars. Later, he led hunger strikes at Alcatraz, Leavenworth and Marion, Ill., prisons, spending time in solitary confinement each time as a result.

But now his eyes are softer, he laughs easily, and he compares politics to the music that he studied in prison. He loves to play on his guitar. "Occasionally in a melody there is a dissonant note, and that is like a revolutionary idea that leads to a new pattern," he said in an interview. The psychology he read, he said, helped him deal with prison tension and taught him to save his anger for the larger problems of society. He sent the $80-a-month he earned making brushes to his wife and two sons.

At 49, and still boyish, Cancel-Miranda immediately charmed the crowds in Chicago and New York, ecstatically riding on the shoulders of his supporters. Already the Puerto Rican press is calling him "the most charismatic of the four" and speculating on his political future.

He doesn't worry much about that. "My father has a furniture store. "Won't die of hunger," he said. "I'll work for the revolution until I die, and if I'm lucky I may find a little time to sing to the children."