Cambridge Bay (Mar 14/05) - Russell Chaulk, 11, and Darcy Evetalegak, 12, know a lot more about catapults than most people in Nunavut.

The pair even built a working model of the trebuchet variety - that's the kind used by the Greeks and Romans.

"Gravity pulls down a counterweight to launch the stone," said Chaulk.

Rosemary Mala, 12, looks up from examining salt crystals through a microscope - her project won the research category at the Kullik - John Curran/NNSL photo

"The other two kinds, mangonel and ballista catapults, use torsion to launch."

"I enjoyed working on the project a lot," said Evetalegak, adding he might like to become an engineer one day. "Putting it all together was fun."

Their catapult, designed to fire marshmallows, earned them top spot in the experiment division of the school's first science fair in three years.

In the other division, Rosemary Mala, 12, captured first place in research for her project on crystals.

She learned a lot including that there are 13 different kinds of crystals and that as they grow bigger they get stronger.

"My favourite part was actually making one," she said.

Mala used monoammonium phosphate to grow a giant specimen, which almost covered an entire dinner plate.

"I like the aquamarine," she said, adding a crystal's colour depends on its chemical composition.

Grade 4 teacher Ruth Roberts organized the fair along with help from Cathie Rowan who co-ordinated the judging.

As good as it was to get the more than 100 students learning about science, Rowan said the fair served a much bigger purpose.

"It was great to see the students go from being shy with the judges to being confident," she said.

She said all of the 57 projects on display in the school gym were tremendous, but Mala, Evetalegak and Chaulk won because they seemed to have an edge.

"The big thing was they really knew their stuff," she said. "They found something that really interested them and that's important."