TO THE MOST SERENE PRINCE HENRY, PRINCE OF WALES,

DUKE OF CORNWALL, &c.

Most Serene Prince, having for two or three years now given some lessons in perspective, and having recognized since I have had the honor of being in the service of your Highness how much you delight in all sorts of sciences, this emboldened me to bring the said lessons to light in the French language, insofar as it seems to me that this science has not yet been demonstrated in that tongue; for what has been done until now has not been demonstrated by any reason. And among the sciences depending on Mathematics, this one is so necessary that it is difficult to arrange works of both Architecture and painting well without having some knowledge of it. And as Vitruvius a Roman architect and engineer of the 1st century BC says in Chapter 2 of his first book of Architecture, Architecture is an arrangement of good conveniences of the parts of a building, of proportion, measure, distribution, and decoration, which parts together the Greeks call taxis order/arrangement. Afterward, one must seek to give grace to every quality of work by a good placement of the members, which the Greeks call diathesis disposition, which comprises three species that they call Ideas. By the first (which is called Ichnography ground-plan) is understood the plan or terrace of the descriptions and lines of the platforms. The second species (called Orthography elevation/upright drawing) is a representation of the raised figure of the body or building. Thus, by the third (named Scenography perspective projection), one sees the shading or recess, with the shortening of the front and the sides of an edifice, made by the reason of perspective. In these three species declared above, born from the imagination and invention of the engineer or Architect, is observed the eurythmy proper proportion/harmony of the Greeks: which is a convenience such as your Highness desires to be kept in the making of your buildings and works. I have also made in this present book some demonstrations for placing shadows on solid bodies: it is a part of perspective very necessary for painters, for one cannot represent anything well in painting if the shadows are not made with some reason. Furthermore, I have also demonstrated the manner in which solid bodies are represented in mirrors, a thing fairly little treated heretofore. I could well have increased the whole with many other figures if time had permitted me; but the works of your Highness occupy me in such a way that I have been constrained to put an end to the present work, hoping to have in some time the leisure to finish another work already begun. And in the meantime, may it please your Highness to find this little labor of mine agreeable, and I shall always pray to God that it please Him to increase your Highness with His holy blessing, and to give you a long and happy life. From your house of Richmond, the first day of October, 1611.