Figures on a Descending Plane
In this case (Fig. 100) the same rule applies as in the previous problem, but as the road on the left is going down hill, the vanishing point of the inclined plane is below the horizon at point S·; AS, BS is the vanishing scale on the level plane; and A·S·, B·S·, that on the incline.
Fig. 100.
Fig. 101. This is an outline of above figure to show the working more plainly.
Note the wall to the left marked W and the manner in which it appears to drop at certain intervals, its base corresponding with the inclined plane, but the upper lines of each division being made level are drawn to the point of sight, or to their vanishing point on the horizon; it is important to observe this, as it aids greatly in drawing a road going down hill.