Florentine perspective and the development of modern science

Perspective in Renaissance was obtained by nzeans of two methods, as found out by researchers: the first one, which consists of combining a horizontal plan, a point of view and a vertical plan, thus obtaining figures in three dimensions, was in 1428, masterly described by Leotze Battista Alberti in his treatise De pictura, translated fronz the latin original to italian by himself in 1436. The second method usually called perspective by points of distance was published in 1580, though it had been used for many years before, as we know now.Alberti's contemporaries, An-tonio Manetti and Filarete, in their writings, claim that architect Brunelleschi, by means of studies with plane tnirrors, preceded Alberti in the discovery of perspective. Their evidences, however, are not etztirely fullfilling. Inspired in the aforementioned authors, we introduce in this paper a very simple instrument which is composed of a fixed mirror, and a plate with an eye hole (a view-finder). This device enables us to verify that the points of distance characteristics is a property of plane mirrors, so it is possible, through experiments with mirrors, to deduce the principal rules of perspective, thus strenghtening Manetti's and Filarete's evidences. Furthennore we will try to prove that we may recognize, based on that verification, some important consequences for the history of art and science.Dois processos para obtençáo da perspectiva exata, foram registrados na Renascenea. 0 primeiro consiste na obtençáo de figuras reproduzindo a profundidade, pela combinagdo de um plano vertical, um ponto de vista e um plano horizontal; foi descrito magistralmente por Leone Battista Alberti em 1428 ein eu tratado De Pictura �em latim� traduzido para o italiano pelo autor em 1436. 0 segundo, frequentemente chamado de perspectiva pelos pontos de distancia, sofoi publicado em 1580, mas se sabe que era praticado muitos anos antes. The second tnethod usually called perspective by points of distance was published in 1580, though it had been used for many years before, as we know now. Antonio Maneni e Filarete, contenzporaneos de Alberti, em seus escritos, reivindicam para o arquiteto Bruneleschi a precedencia da descoberta da perspectiva exata, em relaçáo a Alberti, atraves de estudos com espelhos planos. Entretanto, esses testemunhos seapresentam incompletos. Aqui se descreve um instrumento muito simples, inspirado nos autores citados, composto de espelho fixo e visor, onde se verifica que a caracteristica dos pontos de distancia é uma propriedade dos espelhos planos e, portanto é possivel deduzir as principais regras da construçáo da perspectiva exata, a partir de experiencias com espelhos. Reforga-se assim, o testemunho dos escritores mencionados. Ein seguida procura-se expor algumas consequencias para a historia da arte e da ciéncia, que se pode extrair dessa verificagtio