St. Johnsbury, Vt. — Students at the Arlington School in St. Johnsbury built a catapult out of junk materials and field-tested it last week. The device hurled water bottles, toy pumpkins and balls. At one point the students launched a watermelon, which came crashing down with a calculated splat 40 feet and seven inches away.

The design was a combination of carport steel, PVC pipes, garage door springs, bungee cords, a little wood and a shovel head. It was created by the school’s science, technology, engineering and math class under the direction of teacher Joe Cornelius. “We’re learning basic laws of science and mathematics through hands-on experiences,” said Cornelius, who is finishing his first year teaching at the alternative high school.

“It took us probably three weeks to build this,” said Cornelius. “It’s not the only thing we build. We built a solar car, we built a hovercraft. The kids really like it. They really enjoy doing it and they’ve done a great job.”

He said the design phase was definitely old school and involved a lot of trial and error. “You start out with the parts and whatever you’re building kind of designs itself based on what you have,” said Cornelius.

One of the builders was Arlington School student Logan Thompson. “We were writing down ideas on the chalkboard and we all decided to do that,” said Thompson. “We all put it together and it looks like it’s pretty fun. … We should probably thank Mr. Gammell at the St. J dump because we got most of our materials from the metal recycling tank.”

St Johnsbury Police Chief Clem Houde was on hand to watch the test firing. He had heard the school was looking for a place to test the creation and put in a good word with town officials.

“It’s great to see students engaged in this kind of project,” said Houde. “Plus, it’s pretty cool.”