THE HORIZONTAL LINE IS A LINE AT THE HEIGHT OF THE EYE PARALLEL TO THE GROUND LINE.

Fifth Definition.

Of this line, little will be said hereafter, in that the point of sight and distance represents the horizon.

THE CUT LINE IS AN IMAGINED LINE RAISED AT RIGHT ANGLES UPON THE GROUND LINE WHICH CUTS THE VISUAL RAYS.

Sixth Definition.

The cut line often referred to as the picture plane is so named in that it is cut by all the visual rays that depart from the visible thing and come to the eye; it is this which receives the object of the visible thing as would a flat glass.

THE POINT OF DISTANCE IS THE FOOT OF THE FIGURE THAT LOOKS AT THE VISIBLE THING.

Seventh Definition.

The point of distance original: "eslongnement" is the point where the foot of the figure that looks at the visible thing is. Which point must always be placed at a reasonable distance, for if it were too close to the visible thing, the foreshortening would be monstrous, that is to say strange to the sight. The distance, therefore, that we shall give to the said point of distance will be according to the size of the thing that we see. If it is a surface of twenty feet square, in order to have a beautiful foreshortening, it will be necessary to place the said point of distance at least double the size of the thing; practice will show all of this.