ing unclosed will contain two quarters,
while the one in the right shall have disappeared.

[Illustration: Disappearing Coin]

** Sticking a Coin Against the Wall [176]

Cut a small notch in a coin--ten cent piece or quarter will do--so
a small point will project. When this is pressed firmly against a
wood casing or partition the coin will stick tightly.

** A Chinese Outdoor Game [176]

The accompanying illustration shows the "grand whirl," or the
Chinese students' favorite game. This game is played by five
persons, four of them turning around the fifth or central figure

[Illustration: Chinese Doing the Grand Whirl]

with their arms locked about each other and the two outside
persons swinging in midair with their bodies almost horizontal.

** Home-Made Photograph of a Lightning Flash [176]

How many times has each amateur photographer tried to photograph
the lightning's flash? Some good pictures have been obtained by a
ceaseless effort on the part of the operator. Here is a method by
which you can make a picture of a streak of lightning on a clear
night in your own house. Paste two strips of black paper on a
piece of glass that is 10 in. square so as to leave a clear space
through the center 2-in. or more in width. Smoke this uncovered
space over a candle's flame until the soot is thick enough to
prevent light passing through. Take a sharp lead pencil and
outline a flash of lightning upon the smoked surface, using a fine
needle to make the smaller lines, and then set the glass up
against the back of two boxes which are set to have a space
between them of 4 or 5 in.

A lighted candle is held behind the glass so the light will shine
through for focusing the camera. After darkening the room set your
camera ready for the exposure and burn a small quantity of flash
light powder in the same place in which the candle was held. This
will make an impression upon the plate of the flash drawn on the
smoked glass.

[Illustration: Lightning Flash]

** How to Make a Static Machine [177]

Static electricity is produced by revolving glass plates upon
which a number of sectors are cemented; these sectors, passing
through neutralizing brushes, distribute electric charges

[Illustration: Details of a Homemade Static Machine]

to collecting combs attached to discharging rods. The glass
selected for the plates must be clear white glass, free from
wrinkles, and of a uniform thickness. Two plates are nece