Ægidius Elling

He built the first gas turbine that was able to produce more power than needed to run its own components.

Elling understood that if better materials could be found, the gas turbine would be an ideal power source for airplanes.

Elling also did significant development work in other areas, such as steam engine controls, pumps, compressors, vacuum drying et cetera.

In 1914 Elling produced a book called Billig opvarmning: veiledning i at behandle magasinovner økonomisk og letvint.

(English: Cheap Heating: Guidance for the simple and economical treatment of base burners), which was published by Aschehoug.