Abstract: To increase in particular the level of efficiency in the conversion of sea wave energy into electrical energy there is proposed a wave power generating installation having a chamber for the positive guidance of an oscillating water column, wherein the chamber which is closed in itself below the surface of the water has an opening through which water flows into the chamber and then out again, and a means for taking mechanical energy from the oscillating water column and for converting the mechanical energy into electrical energy. The generating installation according to the invention is distinguished in that the means includes a float body device carried by the water column and a linear generator having a stator and an actuator, wherein the float body device is mechanically operatively connected to the actuator of the linear generator and the actuator for generating electrical energy is reciprocatingly movable by the movement of the float body device relative to the stator of the linear generator.

Abstract: A measure to use to draw a line perpendicular to a reference line. The measure comprises a top surface with opposite first and second ends and opposite first and second edges that extend between the first and second ends. The top surface has a first set of indicia that represent a first scale and a second set of indicia that represent a second scale. The first and second scales are distance scales and have a common zero point. The second scale is a multiple of the first scale. The first and second scales are used to construct the two sides and the hypotenuse of a right triangle with one of the two sides being on the reference line so that a line perpendicular to the reference line can be constructed with little or no calculations required by the user.