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."