1498. Natural beauty of ground. As the right lines and geometrical forms of the architect take the lead in grounds of artificial beauty, so the flowing and broken lines and undefined forms of the landscape-painter take the lead in those of natural beauty. To create them in ground, is generally impracticable and unadvisable; but where they exist concealed by accidental deformities, or incomplete in expression through dulness in their leading features, art may relieve from the impediments to beauty, even though the situation may be at some distance from the eye. In recluse scenes immediately under view, art may aspire to create beauty even from a tame flat, but especially from its opposite, a flat abounding with deformities. In effecting all these purposes, the same principles apply. The first thing to fix in the mind is the desired surface, or that style of natural ground which is best to be imitated. The next thing is to examine on what parts, forms, and lines, the natural beauty of this ground chiefly depends; if undulating, whether the concave or the convex prevails; if broken ground, whether horizontal and perpendicular, or curved and inclined lines prevail. These are then to be imitated in the improvement, ever keeping in view the important principle of forming a whole.