By placing the Ground-line in this, much more remote from the Horizontal, than it is in the foregoing Figure, all Confusion is here avoided. The rest is evident from what has been often said on this Head, and a bare Inspection of the Figure. Parallels to the Ground-line must nevertheless be continu’d to the Visual TO, which falls without this Page; that from them may be rais’d the Elevation of the Length of this Design, which we shall handle in the next Figure.
Fig. xliv.
FIGURA Quadragesimaquarta.
Contractio elevationis figuræ quadragesimæprimæ.
Rectæ parallelæ ad lineam plani figuræ quadragesimætertiæ, ubi pervenerint ad visualem TO, continuandæ sunt, more solito, cum parallelis ad lineam perpendicularem. In hanc autem transferre oportet omnes divisiones, quas ex Barozzio habet elevatio hujus ordinis; ac ducere visuales. Quomodo autem, adminiculo visualium & parallelarum, compleatur elevatio, constat ex figura, & clarius ex chartula figuræ quadragesimæsecundæ. Numeri 1, 2, 3, 4, geminati, ostendunt centra & altitudines semicirculorum seu arcuum figuræ quadragesimæquintæ; videlicet, numerus inferior designat centrum, superior verò designat altitudinem semicirculi.