The Architecture of Vignola put in Perspective; and first, the Pedestal of the Tuscan Order.
Since every one is acquainted with Vignola’s Architecture, I determine not to alter it, but to explain it, with its general and particular Rules; measuring the same with Modules, after the usual manner. He therefore that has it not, may find it in the following Figures, and at the same time learn the Method of putting it in Perspective. And whereas the Drawing the Plan, Elevation and Profile of what’s to be built, is no less necessary for him that studies Perspective, than for the Architect, the first performing in Appearance, what the latter does in Reality; I have therefore here delineated the Tuscan Pedestal, with its Plan, as you see in AB, that you may the better apprehend what I said in the foregoing Figure, That from all the Angles of Projecture in the Elevation, Lines must be let fall on the Plan; this being of absolute necessity for finding the Correspondence of the Angles with the Lines in the Perspective Projection. Observe, that what I always call Length, as from F to G, is that from which proceeds not only the Foreshortning of the Plan; but also that which I call the Profile E. Wherefore, in the opposite Pedestal of the same Figure, you’ll see a contrary Disposition of the Whole.
I shall not here repeat, how the finish’d Pedestal is taken from these; having so largely spoken of that before; but briefly tell you, that the Angles of the first Out-line of the Profile E give the level Lines of the Face D, and the Angles of the Plan give all the Perpendiculars.
FIGURA DECIMA.
Stylobata Doricus, & ratio vitandi difficultatem quamdam, quæ occurrit inter illum opticè delineandum.
Hic oritur difficultas hæc. Vestigium A opticè translatum in C adeò contrahitur, ut distinctè videri nequeat ubi collocetur circini pes, ut transferri possint perpendiculares stylobatæ adumbrati; totaque hæc difficultas oritur à propinquitate quam habet linea horizontalis, seu punctum oculi cum linea plani. Ut igitur illam vincas: Duces lineam plani inferiùs quantum libuerit, & super illam feres denuò latitudinem, & longitudinem more solito, retinendo puncta oculi, & distantiæ OF, & sic videbis vestigia magis minusve distincta; Vestigium enim E distinctius est vestigio D, & D distinctius est vestigio C.
TENTH FIGURE.
A Dorick Pedestal, with the Manner of shunning a Difficulty, which occurs in putting the same in Perspective.
In this Figure a Difficulty arises, which is this; That the Plan A put in Perspective in C, is so foreshorten’d, that one can’t see distinctly, where to place the Compasses, for transferring the Perpendiculars on the shadow’d Pedestal; which is caus’d by the too near Approach of the horizontal Line to the Ground-line. For avoiding this Difficulty, draw another Ground-line as much below the first as you please, and carry the Breadth and Length thereon, after the usual manner, still keeping the same Points of Sight and Distance O and F: And according to the Removal of the Ground-line, the Plans will be more or less distinct; as you see the Plan E is more distinct than D, and D is more so than C.