And that the serpentine line, by its waving and winding at the same time different ways, leads the eye in a pleasing manner along the continuity of its variety, if I may be allowed the expression; and which by its twisting so many different ways, may be said to inclose (tho' but a single line) varied contents; and therefore all its variety cannot be express'd on paper by one continued line, without the assistance of the imagination, or the help of a figure; where that sort of proportion'd, winding line, which will hereafter be call'd the precise serpentine line, or line of grace, is represented by a fine wire, properly twisted round the elegant and varied figure of a cone.

-- William Hogarth