Young visitors are so intrigued by displays at the Howard B. Owens Science Center, a $1.7 million learning center in Greenbelt that Prince George's County maintains for its students, that the exhibits' mechanical switches once tended to wear out after two months, center director Hays B. Lantz says.

The switches on the more popular demonstrations, such as the electromagnetic parachute drop and the heat diffusion tank, tend to last longer now that Newton Likens, the staff technical designer, has installed touch-sensitive contact switches that rely on skin moisture. Likens says he gets excited when demonstrating his handiwork and his palms often are too dry to throw the new switches.

"Sometimes I get so hyper when I'm showing I have to lick my fingers because I'm not conductive enough," said Likens, as he showed the innards of an automated hot-air balloon launcher that shoots a multicolored canvas sphere up three stories.

Since the 1970s, the Prince George's County public school system has become increasingly interested in science, and the Owens Center is the result of that interest, school officials say.

Open since 1978, the facility has specialized in scientific equipment to demonstrate phenomena in biology, optics, computer science, physics, chemistry, astronomy and other fields. About 70,000 of Prince George's 108,000 students are expected to visit this year, augmenting their regular science classes, officials said.

The Owens Center is the only one of its kind in the state reserved for the use of a single county school system, officials said. They said the only other comparable facility in the state is the Maryland Science Center in Baltimore, which is more like a museum than an expanded science laboratory and which is open to the public.

On a recent morning at the Owens Center, five groups of students, ranging from first through eighth graders, were using the center, a three-story brick building set back in a wooded area off Greenbelt Road. It is distinguished from two public schools that flank it by the six-foot windmill generator on its terraced roof.

In the pit of a mini-amphitheater, a teacher was getting "oohs" and "aahs" from third graders as she made a liquid change from clear to purple and back again. In the rear of the building, 30 first graders sat in the 176-seat planetarium surrounded by sun, moon and stars--flung against the vaulted ceiling by a special $500,000 projector.

Upstairs, 8-year-olds were making a room full of minicomputers chatter as they programmed movements of an electronic turtle on green video screens.

Displays at the Owens Center range from a nine-foot python named "Monty" that children can play with to a gas-fired "flame organ" that lets a young experimenter control the physics of wave mechanics and see the results in a three-foot-long row of dancing flames.

"One thing that I would like to be a scientist for would be to help people cure the diseases that they have," said 9-year-old LaShawn Duffin, whose fourth-grade class was conducting an experiment in arthropod behavior.

Duffin and Bonita Blackwell, 9, were carefully recording the whereabouts of four potato bugs in a covered plastic dish as if it were their first step toward careers at the National Institutes of Health.

Owens Center programs are particularly geared toward planting the seed of the scientific method in the youngest visitors, staff members said. Creating a place to get students engrossed in science is the whole idea, Lantz said.

"Science is really a way of learning and our philisophy is learning by doing," Lantz said. He noted that neighboring Montgomery County, which this year outspent Prince George's by a margin of $3,853 per pupil to $2,708, is planning a similar center, although the county's budget allows for more equipment, particulary computers, in individual schools.

Nationwide, emphasis on science education has increased lately after reaching a low in the early 1970s, when liberal arts and liberal educational philosophies were in vogue, Lantz said. Since then, advances in technology have changed the outlook for jobs in computer work, electronics and other technical fields, said Robert J. Shockley, assistant P.G. school superintendent for instruction.

Interest in science also coincides with worries that the United States might be falling behind in technological know-how, he said.

"It relates to national priorities: How do we stack up against the Russians or the Germans," Shockley said. "Now we're back toward the idea that the nation needs to be strong . . . . It's an upswing of love of country and national pride."

From its beginning, the Owens Center has relied on its big brother across Greenbelt Road, NASA's Goddard Space Flight Center, to help inspire young visitors. NASA donates used equipment and technical advice and its scientists occasionally give lectures. NASA and the Owens Center also plan a student-designed experiment on a space shuttle flight tentatively set for next fall.