Example Suppose The Person Wishes His Card To Be The Twentieth
from the top; and the first time of making the heaps, he says it is in
the third heap; you then look at the table in the perspective, and you
see that the first figure is two; you, therefore, put that heap in the
middle of the pack. The second and third times, you in like manner put
the heap in which he says it is, at bottom; the number each time being
three. Then looking at the pack with your glass, as if to discover
which the card was, you lay the cards down, one by one, and the
twentieth will be the card fixed on.