Time on his hands

What do you do when you are on Christmas break from school? Well, Jon's idea is to make a tank. It actually fires weapons, in this case a scrunched up aluminum foil ball that you see lying on the table. I asked Jon to list the ingredients, and here is the list: duct tape, bailing wire, paper towel roll, aluminum foil, scotch tape, cans and lids, cardboard, hair tie cut in half, nails, screws, and a metal lamp cover.