The other volume has for title _Petri Pictoris Burgensis de Quinque Corporibus Regularibus_. The five bodies discussed in it are, the triangle of four bases, the cube with six faces, the octagon with eight faces and as many triangles, the duodecahedron with twelve faces and as many pentagons, the icosahedron with twenty faces and as many triangles. We shall extract from the dedication to Guidobaldo I. a passage relating to the essay and its author: "And as my works owe whatever illustration they possess solely to the brilliant star of your excellent father, the most bright and dazzling orb of our age, it seemed not unbecoming that I should dedicate to your Majesty this little work, on the five regular bodies in mathematics, which I have composed, that, in this extreme fraction of my age, my mind might not become torpidly inactive. Thus may your splendour reflect a light upon its obscurity: and your Highness will not spurn these feeble and worthless fruits, gathered from a field now left fallow, and nearly exhausted by age, from which your distinguished father has drawn its better produce; but will place this in some corner, as a humble handmaid to the numberless books of your own and his copious library, near our other treatise on Perspective, which we wrote in former years. For it is usual to admit, at the most luxurious and festive banquets, fruits culled by a rude and unpolished peasant. Indeed, its novelty may ensure its proving not unpleasing; for though the subject was known from Euclid and other geometers, it is now [first] applied by me to arithmetical science. At all events, it will be a token and memorial of my long-cherished attachment and continual devotion to yourself and your illustrious house."