Orizzonti perduti (e mai ritrovati)

One of the most fascinating topics in Descriptive Geometry courses is the study of how Infinity should and might be represented through the graphic tools of representation. As is well known, thousands of books and essays have been written on Infinity, all well informed and circumstantial, mainly engaged in the anthropological examination of its semantic evolution. The essay analyzes the geometric, but also the historical-figurative implications of this mysterious object, the “Horizon”, which is both an imaginary place and a philosophical figure open to scientific and representative speculation. Starting from the work of Jean-Victor Poncelet (1788 - 1867), and from his Traité des propriétés projectives des figure (Paris 1882), the text begins with the examination of a simple perspective between the geometric plane and the perspective picture, and then delves into the maze of the graphic-theoretical work of the Dutch architect, painter and engineer Hans Vredeman de Vries (1527 - c. 1607) who in his treatise Perspective, dat is de hoogh-gheroemde const een schijnenede in oft door-siende ooghen- ghesichtes punt ... (2 vols., The Hague and Leiden, 1604-05), with the intensive use of the so-called tiers points, tackles the fundamental exercise of the perspective construction of a square inserted within a circular orbit (foll . 1r, 2r). The image seems to allude to the metaphysical figure of an observer whose incessant retinal motion scans the projective space, but perhaps also the geographical one. The other author analyzed in the essay is the Dutch Samuel Van Hoogstraten (1627- 1678) who, in his treatise Inleyding tot de hooge schoole der Schilderkonst anders de Zichtbare werelt (Introduction to the high school of painting or the visible world), published in Rotterdam in 1678, insists on the action of seeing and on the consequent replicative and illusive representation that derives from it, which would be based on the painter’s understanding and mastery of the optical laws here defined as de Zichtkunst (Art of the gaze). For the painter and essayist from Dordrecht, the eye is overwhelmed by the irriducibility, operating like a dark room, as already in Johannes Kepler (1571-1630), a mere receptor of natural images produced by light. The horizon thus becomes not only a liminal place for environmental perception, but also a metaphysical support for our memories: the final scene of the beautiful and poignant film by director François Ozon (1967), entitled Sous la sable (Under the sand, France 2000) recalls it.