Methods and apparatus for launching projectiles

A method for use with an aerosol spray device containing a flammable liquid, and with a projectile launcher apparatus and with a projectile, the projectile having a closed top end and an open bottom end, the projectile launcher apparatus comprising a chamber and a tube, the tube having an open bottom end and an open top end, the open bottom end of the tube fixedly attached to an opening in the chamber, the tube having a generally constant cross section, the open top end of the tube having a screen or blocking bar there-across,

• the chamber having an input port configured to connect to the aerosol spray device, the chamber having a pressure relief valve, the chamber having a spark gap inside the chamber, the spark gap connected by an electrical cable containing at least two electrical wires to a spark power source, the cable having sufficient length to permit the spark power source to be at least three feet away from the chamber and the projectile;
• the projectile shaped to fit in a slidable way over the tube;
• the chamber having a volume of at least one liter;
• the method comprising the steps of:
• sliding the projectile over the tube;
• spraying some of the flammable liquid into the chamber, thereby yielding a mixture of air and atomized flammable liquid in the chamber;
• pointing the projectile and the tube in a direction that is not downwards;
• activating the spark power source, thereby giving rise to a spark across the spark gap, thereby igniting the mixture of air and atomized flammable liquid, the ignition of the mixture of air and atomized flammable liquid giving rise to a rapid expansion of exhaust gas, some of the exhaust gas passing rapidly out of the tube, thereby propelling the projectile rapidly away from the projectile launcher apparatus.