 Based on these experiments he suggested an ideal mill with four times the effect (per wing area) of the average of five existing mills which he had measured.When he actually in 1899 built a new mill in Askov it was only twice as effective, because of a 7% resistance area.In 1929, only twenty years after la Cour's death, a new Askov mill was built directly according to la Cour's "ideal" and this time the factor 4 was obtained.