John Ernst Worrell Keely claimed the invention of an induction resonance motion motor. He explained that he used "etheric technology". In 1872, Keely announced that he had discovered a principle for power production based on the vibrations of tuning forks. Scientists investigated his machine which appeared to run on water, though Keely endeavoured to avoid this. Shortly after 1872, venture capitalists accused Keely of fraud (they lost nearly five million dollars). Keely's machine, it was discovered after his death, was based on hidden air pressure tubes.