Bill is in fact an expert in this field and refers to his book. He knows potato guns. So many small and not so small boys and girls would like to make a potato canon or bazooka. This is taken from the Backyard Ballistics book. Not only is this a fun activity, but it also teaches you about physics. You need some PVC pipe, glue, a hacksaw, and, of course, some potatoes! You also need an igniter and some hairspray. The potato fires out with some force and speed so adult supervision is required. The bazooka is glued to a connector and a spark is made by the igniter. The hairspray forms the necessary 'fuel' which lights from the spark and ejects the potato from the tube.