1. AN INERTIA SWITCH COMPRISING A BODY, OPPOSED FIRST AND SECOND END WALLS, A SIDE WALL INTERCONNECTING SAID END WALLS TO FORM SAID BODY HAVING A CAVITY THEREIN, A CONDUCTIVE SLUG WITHIN SAID CAVITY, MEANS FOR URGING SAID SLUG AGAINST SAID FIRST END WALL FOR SLIDING MOVEMENT THEREOVER AND ELECTRICAL CONTACT MEANS ON SAID SECOND END WALL AND SAID SIDE WALL, SAID SLUG HAVING A PROTRUDING EDGE WHICH ENGAGES SAID SIDE WALL WHEN ENCOUNTERING CENTRIFUGAL FORCE ON ROTATION OF THE BODY TO FORM A PIVOT FOR THE SLUG, THEREBY PERMITTING THE SLUG TO HINGE ABOUT THE PIVOT WHEN ENCOUNTERING LONGITUDINAL DECELERATION OF THE BODY TO BRIDGE SAID ELECTRICAL CONTACT MEANS AND FORM A CLOSED CIRCUIT BETWEEN SAID ELECTRICAL CONTACT MEANS ON SAID END AND SIDE WALLS.