As we can draw planes by this method so can we draw solids, as shown in these figures. The heights of the corners of the triangles are obtained by means of the vanishing scales AS, OS, which have already been explained.
| Fig. 152. | Fig. 153. |
In the same manner we can draw a cubic figure (Fig. 154)—a box, for instance—at any required angle. In this case, besides the scale AS, OS, we have made use of the vanishing lines DV, BV,
to corroborate the scale, but they can be dispensed with in these simple objects, or we can use a scale on each side of the figure as a·o·S, should both vanishing points be inaccessible. Let it be noted that in the scale AOS, AO is made equal to BC, the height of the box.
Fig. 154.
By a similar process we draw these two figures, one on the square, the other on the circle.
| Fig. 155. | Fig. 156. |