Douglas Self, audio design, Subjectivism, Combat Cutlery, Compressed-Air Amplifiers, ElectroMechanical Amplifiers, optical telegraphs, Auxetophone, heliographs, voicepipes, Monowheels, Diwheels, Schilovski Gyrocar, Gyrocars, Brennan Gyro-Monorail, Steam-Powered Bicycles, Rocket-Powered Bicycles, Unusual Bicycles, Unusual Tricycles, Quadcycles, quadricycles, Steam Lawnmowers, Steam Aeroplanes, Unusual Steam Locomotives, Armoured Narrowboat, Jet-Propelled Paddleboat, Helicogyre, Cyclogyro, Propell