The Magician's Own Book, or, the Whole Art of Conjuring / Being a complete hand-book of parlor magic, and containing over one thousand optical, chemical, mechanical, magnetical, and magical experiments, amusing transmutations, astonishing sleights and subtleties, celebrated card deceptions, ingenious tricks with numbers, curious and entertaining puzzles, together with all the most noted tricks of modern performers.

by George Arnold; Frank Cahill

Let your plan be what is shown in the square portion of Fig. 25; at the top of this plan place your triangle, draw a line through the center of the square upwards, until it meets the top A of the triangle. Next draw lines from the corner of the beds parallel to the center line until they meet the base line of the triangle. From thence continue all these lines to the point A. These give you the width of the beds in perspective. The other sides of their figure may be easily enough found. Fig. 26 is the perspective view sought, and is what your experimental drawing would be if, having done the plan and guide-lines in pencil and the rest in pen and ink, you had erased the former with a piece of india rubber.

27

I do not know whether my readers regard the matter in the same light, but it appears to the present writer that this little figure—the triangle—is capable of working wonders in the hands of an amateur draughtsman, if only properly used. Of course, those regularly educated, or submitted to a long course of training as artists, are not referred to, but only the general public, which by the by, means nineteen out of every twenty individuals. I ask whether the preceding cut is any exaggeration on the average sort of result attained, not only amongst very juvenile experimenters, but those of maturer age?

28

Everybody possessed of vision can tell, ordinarily, whether a building or other object is upright, or in the position proper to it, or necessary to its stability. By accustoming the hand to form lines, ovals, circles, squares, and triangles, and by habituating the mind to form comparisons between objects, and these and other figures, a person is put imperceptibly, as it were, in the way of depicting them with accuracy.

To proceed—let us take the above misrepresented country residence, and applying to it the previously given rules, see what we can make of it. We would first draw or trace the parallelogram shown in dotted lines; over this, we place a triangle; then drawing an upright line through the center of both, make that the base of another and lengthened triangle, as shown (see Fig. [28]). Thus we get the three lines of the side and roofs; and if we knew the proportionate height of the side window, by marking the same at a, b, and carrying the lines from those points to the apex of the triangle, we get its true perspective dimensions.