Ioan. Baptistae Portae neap. De refractione optices parte, libri nouem (1593)
Porta, Giambattista della, approximately 1535-1615 · Neapoli : Ex officina Horatij Saluiani : Apud Io. Iacobum Carlinum, & Antonium Pacem · leaf 35
DE REERACT. UBER I. \9 fiimmo latiufculae, in imo ardiores , vt commodius ligneis cir¬ culis conftringi pofsint . Haec eadem interdum aquis femiple- na , fundum minus , quim fit , oftendunt . Ratio eft , quod la¬ tera, quae oblique in aquam merguntur , pars immerfa fubli- mior videtur , & infrada,… … E M extra aquam M H infra , igitur M H fublimior videbitur, & fundum ex hoc coardabitur, & fic de caeteris intelligendum. Clarius loquemur. Sit aqua M F E , oculus A, latus obliquum femifubmerfum E M G H ,fit E M fupra aqua , M H fub aqua H videbitur in L,G in I fublimus, magis ergo inclinatum…
Optics
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
![An illustration from A critical examination of those two paintings on the cieling [sic] of the banqueting-house at Whitehall : in which architecture is introduced, so far as relates to the perspective : together with the discussion of a question, which has been the subject of debate among painters : written many years since, but now first published (1754)](https://img.insideoutlibrary.com/img/200/ia-criticalexaminat00high-32-2.webp)
