Fort Simpson (Apr 18/03) - Could there be a cheaper way to build a Mackenzie River bridge? Maybe.

Bompas Grade 4 students Elissa Hazenberg and Joshua Gambler might be on to something.

For their science experiment, they demonstrated how $5 and $10 bills could be folded length-wise to suspend a cup of water between two other cups.

Could that same principle be applied to a one-kilometre span across the Mackenzie? Unfortunately not, said Hazenberg.

It would be "too light" to support vehicles, she explained.

How about a candle-powered boat? Well, Grade 6 student Emily McInnis-Wharton and Jeffrey McKay, who is in Grade 5, showed that they could propel a 10-centimetre long, aluminum vessel using heat and steam from candles.

"Hopefully, somebody might take this idea, turn it into a big boat and save the environment a bit," McInnis-Wharton said.

When a prototype is constructed, McKay said, he'd even volunteer to captain the boat on its maiden test run.

"But the engine would have to be chambered real good," he advised.

Some of the exhibitions at the Bompas science fair didn't have wider applications, but attracted lots of attention nonetheless.

Celine Gargan, a Grade 5 student, demonstrated that a smooth wine glass will "sing" (by rubbing a wet finger around the lip of the glass) but a beveled glass won't emit the same high-pitched sound.

A classmate informed Gargan that the action, if prolonged, will cause the glass to shatter.

Another student who overheard that replied, "Cool. I'll have to go home and try it."

Note to parents: Make sure your kids only have access to plastic cups.

Other experiments examined colours, light, fire and fungi.

There were also several comparisons such as which objects will go faster, freeze faster or melt faster.

Doug Tate, one of the science fair judges, said he enjoyed talking to the students about their projects.

"It's great to see the kids learning the methods of science," he said.