mousetrap burglar alarm quite effective on auto an ordinary mousetrap can be converted into an effective auto burglar alarm two wires with spring clips attached to their outer ends are attached as indicated one clip Is attached to the live terminal of the horn and the other to the metal frame CONTACT point 0 int ae 4 now of wa TO FRA wl 5 he omm va YIL 13 I 1 how mousetrap alarm Is set to slow blow the horn if thief moves the steer ing wheel ot of the car when the trap Is set tile the circuit la Is open when sprung the circuit la Is closed and the horn blows continuously the tra trap p can be placed so that moving either the steering arm or clutch pedal will spring the trigger popular science monthly