Rules and Examples of Perspective proper for Painters and Architects, etc.

FIGURA Secunda.

John James translation

Modus delineandi opticè Quadratum.

Illustration from Rules and Examples of Perspective proper for Painters and Architects, etc. In English and Latin: Containing a most easie and expeditious method to delineate in perspective all designs relating to architecture

Ante descriptionem opticam quadrati A, quod fingimus delineatum esse in papyro separatâ, ducendæ sunt duæ lineæ parallelæ; altera plani, altera horizontis, ut jam docuimus; notando in linea horizontis punctum oculi O, & punctum distantiæ E. Tum translatâ in lineam plani latitudine ac longitudine ipsius quadrati A, ita ut linea CB sit æqualis latitudini, & DC sit æqualis longitudini. Ex punctis B & C fiunt visuales BO, CO ad punctum oculi; ex puncto D fit recta DE ad punctum distantiæ. Demum ubi visualem CO secat recta DE, fit GF parallela ad CB; habesque quadratum opticè contractum.

Compendium temporis & laboris facies, præsertim in schematibus quæ abundant lineis, si chartulam in medio complicaveris, eademque utaris, ut latitudinem ac longitudinem quadrati transferas in lineam plani.