This is a barrel sealing PVC air cannon, with a moving piston sealed against a rubber hose clamp in the barrel. Adding air through the fill valve moves the piston forward, allowing air to leak ...

The Army is maturing technology for a cannon capable of firing hypervelocity projectiles for the air defense mission, ...

For this project, instead of trying to quiet his blower, he decided to make one as loud as possible in the form of an air raid siren ... balancing everything on a marble really seemed to help ...