Abstract: A publicity board provided with a plurality of rotatable prismatic members ounted side-by-side, each being arranged to carry portions of publicity images on its faces, and further provided with a meter for rotating the prismatic members about their respective longitudinal axes. The motor is coupled to the prismatic members by means of an operating shaft driven by the motor and carrying a plurality of radial rods such that they rotate, to each cooperate with respective appendices extending radially from an end pivot of each prismatic member, for the purpose of transmitting to this latter a rotation through an angle which is double the angle formed at the center by each face of said prismatic member.