ript
in the mirror only. The writer will probably go no farther than
the first letter. His hand seems to be struck with paralysis and
unable to write anything but zigzags, says Scientific American.

Another experiment may be made by taking an egg shell and trimming
it with the scissors so as to reduce it to a half shell. In the
hollow bottom roughly draw with your pencil a cross with pointed
ends. Bore a hole, about the size or a pea, in the center of the
cross. Place yourself so as to face a window, the light falling
upon your face, not upon the mirror which you hold in one hand.
Close one eye. Place the shell between the other eye and the
mirror, at a distance of 2 or 3 in. from either, the concavity
facing the mirror as shown in Fig. 4. Through the hole in the
shell look at the mirror as if it were some distant object. While
you are so doing the concave shell will suddenly assume a strongly
convex appearance. To destroy the illusion it becomes necessary
either to open both eyes or to withdraw the shell away from the
mirror. The nearer the shell to the mirror and the farther the eye
from the shell the more readily comes the illusion.

[Illustration: Experimenting with a Mirror]

** Miniature Electric Lamps [434]

After several years' research there has been produced a miniature
electric bulb that is a great improvement and a decided departure
from the old kind which used a carbon filament. A metallic
filament prepared by a secret chemical process and suspended in
the bulb in an S-shape is used instead of the old straight span.
The voltage is gauged by the length of the span. The brilliancy of
the filament excels anything of its length in any voltage.

Of course, the filament is not made of the precious metal, radium;
that simply being the trade name. However, the filament is
composed of certain metals from which radium is extracted.

[Illustration: Types of "Radium" Lamps]

The advantages of the new bulb are manifold. It gives five times
the light on the same voltage and uses one-half of the current
consumed by the old carbon filament. One of the disadvantages of
the old style bulb was the glass tip which made a shadow. This has
been obviated in the radium bulb by blowing the tip on the side,
as shown in the sketch, so as to produce no shadow.

** How to Make a Magazine Clamp [435]

This device as shown in the illustration can be used to hold
newspapers and magazines while reading. Two pieces of wo