n so small,
that each Letter should not occupy more than the hundredth part of a
square Inch._

By adopting the plan of the preceding article, the changes of the
twenty-four letters will be found to be

62,044,840,173,323,943,936,000.

Now, the inches in a square yard being 1,296, that number multiplied
by 100 gives 129,600, which is the number of letters each square yard
will contain; therefore, if we divide the above row of figures,
(the number of changes,) by 129,600, the quotient, which is
478,741,050,720,092,160, will be the number of yards required to
contain the above mentioned number of changes. But as all the 24
letters are contained in every permutation, it will require a space
24 times as large, _viz._,

11,849,785,210,282,211,840.

Now, as the surface of the whole globe only contains
617,197,435,008,000 square yards, it would require a surface 18,620
times as large as the earth to contain them.

_The Enchanted Bottle._

Fill a glass bottle with water to the beginning of the neck; leave
the neck empty, and cork it. Suspend this bottle opposite a concave
mirror, and beyond its focus, that it may appear reversed. Place
yourself still further distant from the bottle; and instead of the
water appearing, as it really is, at the bottom of the bottle, the
bottom will be empty, and the water seen at the top.

If the bottle be suspended with the neck downwards, it will be
reflected in its natural position, and the water at the bottom,
although in reality it is inverted, and fills the neck; leaving the
bottom vacant. While the bottle is in this position, uncork it, and
let the water run gradually out: it will appear, that while the real
bottle is emptying, the reflected one is filling. Care must be taken
that the bottle is not more than half or three parts full, and that no
other liquid is used but water, as in either of these cases the
illusion ceases.

_The Solar Magic Lantern._

Make a box, a foot high, eighteen inches wide, and about three inches
deep. Two of the opposite sides of this box must be quite open, and in
each of the other sides let there be a groove wide enough to admit a
stiff paper or pasteboard. You fasten the box against a window, on
which the sun's rays fall direct. The rest of the window should be
closed up, that no light may enter.

Next provide several sheets of stiff paper, blacked on one side. On
these papers cut out such figures as your fancy may dictate; place
them a