Subject: Flettner's rotor

In the 30th,Flettner developped a vertical cylinder rotating at low speed 
mounted on deck : the rotation causes air to circulate around the cylinder, 
which when struck by the wind, creates a lift perpendicular to the axis of the 
cylinder, hence creates a force which drives the ship forward. The idea was 
tested on a fullsized sailing ship and was proved to be more efficient than the 
old fashoined sails.What happened to that invention ? 

Re: Flettner's rotor