Abstract: A wind mill construction is disclosed, including a rigid tower structure (6, 7) to the upper end of which is connected for rotation about a vertical axis a wind turbine housing (5) to which is journalled for rotation about a horizontal axis a propeller (2) of the two-blade on three-blade type, characterized in that a strip member (8) extends generally helically about the tower structure for counteracting the effects of wind upon the tower and the blades. The strip may be mounted on the upper portion of a tower the base portion of which has a frustoconical configuration. The pitch of the helical strip is preferably no greater than three times the maximum diameter of the upper tower portion.