PART III.
NATURAL MAGIC.
THE MAGIC LANTERN.
The illusions of which we have spoken in the first
part of this work depended principally on the nature of
man's vision, who, we found, was the constant and heed-*less
victim of his own powers of sight. We shall now
examine a series of illusions that are still more extraordinary,
but which have nothing to do with the deceptions
practised on us by our visual organs. Instead of
being deceived by ourselves, we shall find that we are
led astray by others whose knowledge of the laws of
optics is greater than our own, enabling them to construct
instruments capable of amusing us or imposing
on us, according to our ignorance of natural laws. Let
us hope, however, that the science of optics has now
become so familiar to most educated people, that no such
thing as a real imposition can take place, although at
the present day there are so many exhibitions of the
marvellous that ordinary observers have the greatest
