hem, and all outline engravings from pictures, are bad
work, and only serve to corrupt the public taste. And of such outlines,
the worst are those which are darkened in some part of their course by
way of expressing the dark side, as Flaxman's from Dante, and such
others; because an outline can only be true so long as it accurately
represents the form of the given object with _one_ of its edges. Thus,
the outline _a_ and the outline _b_, Fig. 12, are both _true_ outlines
of a ball; because, however thick the line may be, whether we take the
interior or exterior edge of it, that edge of it always draws a true
circle. But _c_ is a false outline of a ball, because either the inner
or outer edge of the black line must be an untrue circle, else the line
could not be thicker in one place than another. Hence all "force," as it
is called, is gained by falsification of the contours; so that no artist
whose eye is true and fine could endure to look at it. It does indeed
often happen that a painter, sketching rapidly, and trying again and
again for some line which he cannot quite strike, blackens or loads the
first line by setting others beside and across it; and then a careless
observer supposes it has been thickened on purpose: or, sometimes also,
at a place where shade is afterwards to inclose the form, the painter
will strike a broad dash of this shade beside his outline at once,
looking as if he meant to thicken the outline; whereas this broad line
is only the first installment of the future shadow, and the outline is
really drawn with its inner edge.[21] And thus, far from good
draughtsmen darkening the lines which turn away from the light, the
_tendency_ with them is rather to darken them towards the light, for it
is there in general that shade will ultimately inclose them. The best
example of this treatment that I know is Raphael's sketch, in the
Louvre, of the head of the angel pursuing Heliodorus, the one that shows
part of the left eye; where the dark strong lines which terminate the
nose and forehead towards the light are opposed to tender and light ones
behind the ear, and in other places towards the shade. You will see in
Fig. 11 the same principle variously exemplified; the principal dark
lines, in the head and drapery of the arms, being on the side turned to
the light.

[Illustration: FIG. 13.]

98. All these refinements and ultimate principles, however, do not
affect your drawing for the present. You must try to