In this way eight types of these congruences have been obtained. The properties of the pedal surfaces of such congruences with the finite pole P have been studied. For the types VI-VIII pedal surfaces break up into the 3rd order surface and the plane at infinity.
Basic classification is made according to the number of their real straight lines.
Further classification is made according to the number and kind of singular points. The methods of synthetic and analytic geometry have been used. The pictures of the surfaces have been constructed with Mathematica 4.0. They are obtained by using standard pachages and make relatively sophisticated shapes easier to see. For the visualisation of synthetically obtained results the animation with Mathematica 4.0 is used.