Bate's Car: Sweet as a Nut (1974)

This short film presents Mr. Bate, an inventor who discovers a substitute for gasoline in barnyard manure. Even though he fits the classic mould of single-minded know-how and practical dreamer, his discovery is tried and tested. He demonstrates how his home-made digester does turn manure into potent methane gas that powers his auto. And for good measure, he demonstrates his latest sustainable invention – a bicycle powered by the bumps on the road.