is higher than your object, in the second drawing it is lower than your object.
Some things have more than one vanishing point—for instance, this same cardboard-box. A box is an angular object. It has two sides which run parallel, and two ends which also run parallel one with another.
Place the box so that two sides can be observed, and sketch it lightly and without measuring. Roughly sketch its position, and decide whether the eye is above or below the top of the box, i.e, whether the horizon is low or high. Then draw the line of the horizon right across the paper, because both vanishing points must be on the same level—at the same horizon.
Young artists find it difficult to accept this fact. They are exceedingly prone to provide a different horizon for each difficult angle.
The horizon at sea runs straight across the line of vision; as you know, it runs level with the eyes. Then why try to reach several horizons in the same picture?
In other words, it is not reasonable to assume two horizons in drawing one object.
