IV. There is one common construction, however, in which, singularly, the hand and eye of the painter almost always fail, and that is the fillet of any ordinary capital or base of a circular pillar (or any similar form). It is rarely necessary in practice to draw such minor details in perspective; yet the perspective laws which regulate them should be understood, else the eye does not see their contours rightly until it is very highly cultivated.
Fig. 71.
Fig. 71. will show the law with sufficient clearness; it represents the perspective construction of a fillet whose profile is a semicircle, such as F H in [Fig. 60.], seen above the eye. Only half the pillar with half the fillet is drawn, to avoid confusion.
[p93]
]Q is the center of the shaft.
P Q the thickness of the fillet, sight-magnitude at the shaft’s center.
Round P a horizontal semicircle is drawn on the diameter of the shaft
a b
.
Round Q another horizontal semicircle is drawn on diameter