This Base is put in Perspective by the Rules before laid down. The Height of the Superficies A is the same with that of the visual Line CD; the Breadth of the Cross A is the same with that of the second Circle of the Plan B, beginning with the least. The two Lines that stand perpendicularly on the Surface of the Base, shew the greatest Breadth of the Columns Shaft above the Fillet. The Extent of the upper Torus and the two Astragals, is the same with that of the third Circle; and the Extent of the lower Torus is the same with that of the outward Circle.
Fig. xx.
FIGURA Vigesima.
Basis Acticurga opticè imminuta.
Basis Acticurga Pictoribus præ reliquis familiaris est, quia cum omnibus ferè Ordinibus egregiè consentit. Porrò ex punctis E & F maximæ utrinque latitudinis extimi circuli vestigii, habetur maxima latitudo tori inferioris CD. Ac cætera quæ spectant ad ipsum & ad torum AB, petenda sunt ex dictis de basi Etrusca.