11. It was driven by a three-cylinder compressed air engine invented designed and made by Peter Brotherhood. 12. In some cases, such as compressed air engines , the engine may be mechanical rather than electrical. 13. Compressed air engines can recharge an electric battery. 14. The inclusion of a regenerator differentiates the Stirling engine from other closed cycle hot air engines . 15. A praxinoscope made by Ernst Plank, of Nuremberg, Germany, and powered by a miniature hot air engine . 16. A very simple thermoacoustic hot air engine is the Rijke tube that converts heat into acoustic energy. 17. In 1872, Gern presented a 6-ton torpedo, powered by a compressed-air engine , but tests showed only modest results. 18. It was the second mid-air engine failure on one of Air New Zealand's passenger jets in recent months. 19. The design was unsatisfactory, and the arms were replaced by indicator lamps interlocked to the air engines in 1924. 20. Rolls-Royce initially offered a variant of the bleed-air engine and would have been developed in partnership with Kawasaki Heavy Industries.
