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Popular Mechanics Co.

"The Boy Mechanic: Volume 1 700 Things for Boys to Do"

As
there is a vacuum in the bulb it will quickly fill with water.
Shake the bulb gently until a part of the water is out and then
screw the bulb into a socket with the point always downward. Apply
the current and the heated air inside will soon expand and force
the water out with great rapidity. Sometimes this experiment can
be done several times by using the same bulb.
--Contributed by Curtiss Hill, Tacoma, Wash.

** Photographing a Streak of Lightning [124]
The accompanying illustration is a remarkable photograph of a
streak of lightning. Many interesting pictures of this kind can be
made during a storm at night. The camera is set in a place where
it will not get wet and left standing with the shutter open and
the plate ready for the exposure. Should a lightning streak appear
within the range of the lens it will be made on the plate, which
can be developed in the usual manner. It will require some
attention to that part of the sky within the range of the lens so
as to not make a double exposure by letting a second flash enter
the open lens.
--Contributed by Charles H. Wagner.


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