Some problems related to ruled surfaces of the 3rd order

Abstract

If through some point on a quadratic cylinder we draw a secant plane (defining the conoprime k), a tangent plane and in it some oblique line d (not in the plane of the curve k and not generating the cylinder), and then from each point of this line we draw in the diametrical plane of the cylinder there are two rays through the points of the curve k, then we obtain a ruled surface of the 3rd order.