s from this upon another
screen, by means of several lights, held by assistants. Thus each
light throws its own shadow, and if the candles are moved up and down,
and about, the shadows will dance, jump over each other, and do all
sorts of wonderful things. Robertson, and other public exhibitors, had
quite complicated arrangements of this kind, but they all acted on the
same principle. But all of those who exhibit to the public the freaks
of light are not as honest as Mr. Robertson. You may have heard of
Nostradamus, who also lived in Paris, but long before Robertson, and
who pretended to be a magician. Among other things, he asserted that
he could show people pictures of their future husbands or wives. Marie
de Medicis, a celebrated princess of the time, came to him on this
sensible errand, and he, being very anxious to please her, showed her,
in a looking-glass, the reflected image of Henry of Navarre, sitting
upon the throne of France. This, of course, astonished the princess
very much, but it need not astonish us, if we carefully examine the
picture of that conjuring scene.

[Illustration]

The mirror into which the lady was to look, was in a room adjoining
that in which Henry was sitting on the throne. It was placed at such
an angle that her face would not be reflected in it, but an aperture
in the wall allowed the figure of Henry to be reflected from a
looking-glass, hung near the ceiling, down upon the "magic" mirror.
So, of course, she saw his picture there, and believed entirely in the
old humbug, Nostradamus.

[Illustration]

But there are much simpler methods by which the vagaries of light may
be made amusing, and among the best of these are what are called
"Chinese shadows." These require a little ingenuity, but they are
certainly simple enough. They consist of nothing but a card or paper,
upon which the lights of the picture intended to be represented are
cut out. When this is held between a candle and a wall, a startling
shadow-image may be produced, which one would not imagine to have any
connection with the card, unless he had studied the manner in which
said card was cut. Here is a picture of a company amusing themselves
with these cards. No one would suppose that the card which the young
man is holding in his hand bore the least resemblance to a lion's
head, but there is no mistaking the shadow on the wall.

[Illustration]

The most wonderful public exhibitions of optical illusions have been
th