Shrieking children and splashing water hardly typifies you usual metropolitan museum exhibit. But then again, with its leapfrog computer games and automobile video displays, the Children's Museum of Boston is not your typical marble and musty chamber.

In fact, with rubber dolphins and cascading waterfalls marking the museum's new exhibit on the physical properties of water, the children's cultural center has been catching a lot of attention lately as Bostonians and tourists alike seek a new way to escape the summer heat wave.

Summer Splash, as the new exhibit is called, is the first show the Children's Museum has moved outdoors to the piers that separate Museum Wharf from the Boston Harbor. And, it has been so successful in attracting both tourists and locals that Museum Publicity Director Gail Eaton says it may one day become a permanent part of the museum's exhibits.

Stationed next to a large white milk bottle that doubles as a refreshment stand, Summer Splash's new yellow and blue awning houses a series of waterfalls that are designed to show children how gravity and other natural forces affect the movement of rivers, lakes and even wells in Africa.

The most popular exhibit seems to be a zigzagging channel of water that acts as a slide, transporting sponges and submarines from one tank of water to another.

Catherine, 10, from Boston, says that she approves of the sliding tank mainly "because they [the sponges] move around on their own. It's not hard to do, like the bubble one," she says.

Another, Leah, age 4 and visiting Boston from New York City's Bronx, said she liked the water slide because "it's so hot I think I might just jump in. I might bump my head though," she said about the 3 foot diameter tank.

The first exhibit shows a group of three tin washtubs standing one above the other, with water flowing from the top one down to the bottom in waterfall fashion. Plastic lobsters and fuschia rubber fish make their way down the tanks until the children figure out how to pump the water back up to the top tank again.

But Jennifer Cohen of Cambridge, who works at the Museum's Summer Splash section, says that the exhibits change daily, and yesterday the children, who average about five or six in age, were allowed to fish for the pre-fabricated aquatic life with poles fitted with hooks on the end.

Some of the kids seemed to enjoy cooperating with each other, one fitting the fuschia head of one fish onto the body of a red one for his sister, but another eight-year-old was more self-absorbed and screamed "gimme that fishing pole!" while swinging another in the air near the waterfall washtubs.

Another washtub houses a series of red, yellow and blue kitchen sponges which float at random in the water. When a child opens the flood gates, the water level begins to rise. The gate-master must determine which way the water is running and how to stop the tub from getting full.

"We spend alot of time with that exhibit showing the kids which sponge floats faster, a dry one or a wet one, and which channel will flow in which direction," says another member of the museum staff. "We're teaching them about physics without actually using that word. They don't really know they are learning."

A third exhibit uses clear hoses and wooden parts to demonstrate the mechanism of a well that Eaton says was fashioned in Africa. "This is how they use gravity to get water in certain parts of Africa," she says. "They move the wheel against gravity and pump the water up to a certain height, and then it falls. See? The children wouldn't be able to see that if the hoses were opaque or green or something. The clear ones demonstrate a natural fact."

Eaton says that the Museum's staff employs several members who are acquainted not only with science but, more importantly, with how to teach children about nature without making it seem as if they are being educated.

"There's more of an emphasis now on kids spending quality time," she says. "Parents want their kids to have fun and to be occupied, but they also want their learning to continue."

To further the children's education, the Summer Splash exhibit has also invited special guest appearances of folk singers, dancers and even a "bubbleologist" to demonstrate the properties of water.

Tom Paxton performed children's folk songs for the Fourth of July weekend, and last week Professor Bubble demonstrated the miracles of surface tension. Next Sunday, the Sea Chanty Singers and Storytellers from the Mystic Seaport Museum in Connecticut will tell children about the New England ocean life, and for its final weekend, Summer Splash will host a beach party complete with 70 tons of imported sand.

"We're going to bring in sand, beach balls, beach games and music to create the atmosphere of a beach right here in Boston," says Eaton. "We won't use the water from the harbor, of course. But we want the beach party to be symbolic of that day in the future when the people of the inner city water areas can use the local water. This all goes along with the Harbor Clean-Up project. We want the water to be enjoyed as clean."

One mother says that she thinks children's museums are great for getting young children active in the learning process but adds that she thinks Summer Splash caters to a slightly older crowd. "We've been to two in the New York area, but this one seems made for older children, ones who are in elementary school or so. I'm not sure how much [my daughter] understands."

If the younger children were comprehending the laws of physics, they weren't about to let strangers in on their newfound knowledge. Questions about how they were enjoying the exhibits usually drew blank stares from the young scientists. When they did answer, they stuck strictly to the empirical. "I'm poking a sponge," said one, who quickly retreated to the comfort of her nearby mother.

Teenagers enjoyed the exhibit as well. As a counselor for the Beth Israel Summer Camp in Worcester, Yael Miller, 17, says she enjoyed the chance to take the campers outside.

"It was so hot in there, and then we saw the water exhibit and said 'let's go.' Of course I've been running around after the kids the whole time in here, but it is alot of fun," says Miller, while two of her co-counselors marvelled over the five foot bubble display.

Donna Boczar, of Sarasota, Florida, whose children were also enjoying Summer Splash, feels that the exhibit is a good learning experience for kids. "I'm surprised at what they're interested in," she says. "I don't really think they think they're learning, but they are."

The ability to pique childrens' interests and teach them without the atmosphere of the stuffy class room is what Eaton sees as vital to Summer Splash's success. If the children enjoy their visit to the water exhibit, then they will ask to come again. But, Eaton adds, were it not for the cooperation of the surrounding business community and for modern trends in child raising, the exhibit would not have been as successful as it has been.

"There are more offices in this area, and with the exhibit's awnings and sign visible, the parents who work near here can see our Museum and may decide to bring their children here," she says. "Also, the area has changed. A lot of business people eat lunch down here and see the exhibit and just decide to walk in. Then they tell others about it."

Eaton also attributes the success of the exhibit to new attitudes toward sun and long days at the beach. "I think more and more parents are beginning to realize that a child's predisposition to skin cancer beings when he is young. So you don't want your child baking out on the beach, but you also don't want him cooped up inside. This exhibit is outdoors but it's shaded and cool, and some parents may be taking advantage of the fact that it's recreational but non-dangerous."

She adds that the Museum planned the exhibit for July without knowing that a heat wave would descend on the city during that month. "The heat has certainly boosted attendance, and we could hardly have planned on that."

The success of Summer Splash, moreover, has made Museum planners speculate on the success of a permanent water exhibit for future summers.

"Let's just say it's a dream that we'll have a water park someday," says Eaton. "It would be wonderful to have a place for art, performances, sculpture, and beach and water that the entire inner city community could enjoy."