With more mothers in the job market, more and more American fathers W are taking an active hand in caring for their children, pitching in on everything from bottle feeding and diaper changing to show-and-tell in their children's pre-school.

As part of an innovative program at the Friendly Child Care Center, 2121 Decatur Place NW, many of the fathers of the 25 toddlers recently visited the center to explain to the children what they do for a living or as a hobby.

Richard Turner, an architect, sat down on the floor with the children with a set of building blocks to show them how to build bridges and buildings.

Steve Nichols, an attorney with a law firm that represents electrical cooperatives, passed around pictures and a toy windmill as he explained how windmills are used to generate electricity.

Clarence (Sunny) Powell, who installs locks and security systems, brought his tool kit and let the children look through door security peepholes as he explained the importance of a secure home.

One father showed slides of a camping trip and set up a tent, while others demonstrated how to play the guitar, how to use a camera and how to draw.

"It is sometimes difficult for men to feel comfortable with children, so the program is designed to give fathers a structure to participate in the child's early development and education," said Jim Clay, head teacher at the Quaker-run day-care center. "The children get to know what dad does for a living and to feel he is involved with them, and dad gets to watch his child with other children."

Many of the fathers of the children at the day-care center say they find parenting quite rewarding. Powell said the task of early child care fell to him because he and his wife both needed to work, and his job was the more flexible. So for 2 1/2 years he carried his son Brian, now 3, to work with him each day until the boy was enrolled in the day-care center a few months ago.

"I had a backpack and a child safety seat for him, and I took him everywhere I went, bottles, diapers and all," said Powell, who works for the Security Group. "The guys on the work sites made fun of me, and my partner was really embarrassed, because he's 45, and the idea of a father carrying a baby around to work was completely out of his comfort zone."

But Powell, 32, said he has no regrets about his early liaison with his son and said all fathers should be more involved with their children. Powell and the other young fathers interviewed were active in parenting even before their children's birth, both in preparatory childbirth classes with their wives and in the delivery room when circumstances permitted.

In another case the initial emotional "bonding"--the immediate physical contact that usually occurs between mother and child and is thought to help cement the emotional closeness between them--first occurred between father and child.

"My son Matthew was delivered by Caesarean section and my wife was in intensive care, so I was the first to hold our son," said Richard Turner, 31, an architect with Bernard Johnson Architects and Engineers. That strong bond continues, according to Turner, who used to pick up his 3-year-old boy each day for lunch before his office recently was moved out of the District.

Some fathers admit they had to overcome initial discomfort in their new, more active parenting role. Steve Nichols, 37, said that although he took part in childbirth preparatory classes and was in the delivery room when his child was born, nothing quite equaled the reality of caring for a tiny baby.

"This was my first experience with changing diapers and giving bottles and at first I felt very awkward trying to handle a baby," said Nichols, an attorney at Spiegel & McDiarmid. "But it is fascinating being intimately involved with a child from age zero on, and actually it seems the natural thing to do."

Psychologists say this increased involvement in parenting by fathers is too recent a phenomenon for them to be able to determine its impact as the child matures, but past studies indicate that an active father is a positive influence.

"A nurturing father creates a more loving relationship in the family," said Fariyal Ross-Sheriff, associate professor in the school of social work at Howard University. "Several studies show that the best adjusted adults are those with warm relationships with both parents in a family setting, although well-adjusted adults also come from a loving one-parent home."

She said the most thorough review on the subject is "The Role of the Father in Child Development," edited by Michael E. Lamb, and published by John Wiley & Sons in 1976.

This new type of father is a by-product of several social phenomena, including the women's movement, which has stressed equality of the sexes and has put more women in the workplace, requiring more sharing of duties in the home.

"Traditionally the mother was seen as the expressive parent who is warm and nurturing, while the father was the instrumental parent who is the financial provider," said Ross-Sheriff.

"But now, because the mothers are in the labor market, the father's participation is not just a luxury, but a necessity. And father is not just feeding and changing baby, but is qualitatively more involved in that he spends time playing with and amusing the child," she said.

In addition to the general changing of traditional social and sexual roles, the movement toward natural childbirth, in which the father can play a significant role, gives fathers a greater early involvement with the child.

Dr. Linda Brandt, associate professor of clinical and developmental psychology at George Washington University, said there is no true stereotype of the "new father," but that he is often "under 35, middle-income, well-educated and well-intentioned."

The new fathering trend is not limited to young fathers, however, but is slowly expanding to include older men.

"While it's primarily new fathers who are finding the interest and the willingness to make some changes in their lives to spend more time with the children, fathers of middle-childhood and even teen-aged children also are changing the way they behave with their children," said Brandt. "And it is a positive change no matter what age the child is."

Robert Roach, 43, said he had been a parent for 22 years before he discovered the true joys of fatherhood. Roach spent 20 years in the Navy, so he missed the development of his two daughters, Amecia, 22, and Verlincia, 20.

After he retired, Roach said, he realized how much he had missed when his wife's work schedule forced him to care for their two young sons, Rodney, 12, and Alfonso, 9. Roach said he now enjoys close ties with all his children, particularly the boys, with whom he plays ball and goes bike riding.

"I was gone so much when my daughters were growing up that once I picked one of them up and she cried because she didn't even know who I was," said Roach. "My boys never lost sight of who daddy was, but could take me or leave me because I was gone so much. Now I'm home more and while I know I can't make up for my absence, I still feel I can give something, even if only conversation."

According to Rodney Roach, his father's interest was better late than never.

"When my dad was always gone, it seemed like I had nobody to look up to," said Rodney, a seventh grader at Walker Mill Junior High School in Capitol Heights, Md. "But now he's teaching me how to use tools to fix bikes, and we're building a basketball court together. Now I think my dad is one of the nicest people I know."

Although the military life can make it difficult to maintain a cohesive family unit, other institutions are slowly recognizing the father's right to be an active parent. The D.C. public school system has a "paternity leave" policy that allows a father, like the mother, to take up to two years' unpaid leave for child care without jeopardizing seniority in the school system. And for federal workers, the experimental flexitime policy permits a working father to schedule more time for parenting if he chooses.

The courts also are recognizing the father's growing role with his children. Most states, and the District of Columbia, have wiped out laws that gave preference to the mother in child custody cases.

Doris Jonas Freed, chairperson of the custody committee of the American Bar Association's Family Law Center in New York, said the latest trend is a preference for joint custody. She said about half the states already have joint custody provisions on the books, while others have bills pending in their legislatures.

"As recently as five years ago, men were discouraged by their attorneys from seeking child custody" in divorce cases, said Freed. "But now the courts recognize that fathers do a lot of parenting, and should be allowed to continue that role even if the marriage ends."

Freed and Brandt agree that in the United States, the trend toward fathers taking an increased role in parenting is less than 10 years old. But it has been long awaited and is much welcomed, say some young mothers, particularly women who once worried about choosing between career and family. A helpful father helps them to have both.

"I love it that my husband is such a tremendous support with our son, and I feel it adds something extra special to our relationship," said Beth Powell, a legal secretary for a downtown law firm, and wife of Clarence Powell. "Even though I was still nursing our son, I was able to return to work sooner because my husband would bring the baby down for me to nurse on my lunch hour."

Richard Turner's wife, Elizabeth, said she is able to pursue graduate study at the University of Virginia only because of the shared child-care arrangement with her husband. In addition to 3-year-old Matthew, the couple also has 9-month-old twins, Scott and Emily.

"I not only welcome his interest, but it's absolutely necessary with the twins," said Elizabeth Turner. "I see it as a partnership, but I couldn't survive without his help."

Brandt said she has heard of cases, but has not encountered any, in which a mother may perceive of her nurturing father-husband as an infringement on her traditional role as mother.

"Some mothers are used to taking total care of baby and sharing this could be difficult for them," she said. "But in most cases, women are pleased to see the greater interaction of men and it seems to build a stronger family unit."

"The role of the father is important, particularly in early child care from birth up to five, because as these are the crucial formative years," said Ross-Sheriff. "And I hold that fathers can be as nurturing as mothers because it's not in the genes but in the socialization."