Sigurd Johannes Savonius

One such experiment, an attempt to mix red phosphorus with a knife and fork, cost him two fingers and the sight in his right eye.

He met his future wife, the Englishwoman Mary Appleyard (born 1884), through his brothers, who were students in her English class.

He and his wife had seven children: four daughters (Moira Angela Hjördis (born 1914), Ann-Mari, Mary Henrietta and Gustava Elisabeth) and three sons (Klas Albin, Mark Adrian Briggs and Johannes Anthony (born 1916), who died in hospital on 8 March 1940 from wounds sustained in the Winter War).

The idea was to take advantage of the Magnus effect: the perpendicular force exerted on the enclosed cylinders as they spun at greater than wind speed.

Savonius wondered whether the ship could be driven by a rotor apparatus operating by wind power alone, without the aid of an engine.

He met with Flettner in the offices of his firm, Savonius & Company, on Lönnrotinkatu Street in Helsinki, and the two engineers conducted experiments there.

But a short biography of Savonius has suggested that such an application could well be possible, provided that a technical solution is found to convert the rotational motion of the cylinders into thrust.