The goal of this paper is based on the fact to conjugate and compare some considered significant observations based on the descriptive geometric graphic experiences. It considers the descriptive geometric graphic process as a whole, namely to always sustain the consideration of the geometric continuity in the change from a representation system to another. As a result it was possible to also compare the historical thought belonged to a particular historical season training inherent in the Neapolitan school of descriptive geometry referring in particular cultural attitude of Vincenzo Flauti (1782-1863). The method of study concerned the meaning of drawing according to the rules established ordered on geometric relationships codified and to order the knowledge acquired on the basis of a... recognized and precise meaning, now general, particular now. In this way it is always confirmed the geometric relationship decreed by the relation that exists between the projection and the image, understood as inseparable units, as they generate a displayed model that derives from the geometric structure of a fixed model and determined by the type of system used for the representation of an object. Move from one system to another as from the perspective orthogonal projection homological, as well as understand the processes and geometric forms defined in space and plan it helps to ensure the extraordinary nature of the descriptive geometrical drawing and consider its historical evolution experimented and analyzed as the visible part of our future, here understood as the act of a logic and a reason in doing and in research.