If two of them are floating on the
same solution, they will move about and finally arrange themselves
end to end with the coils and magnet cores pointing north and
south.
--Contributed by C. Lloyd Enos.
** A Fish Bait [152]
A very effective fish bait is made by inclosing a live minnow in a
short section of glass tube, which is filled with water and both
ends closed with corks. This is used in place of the spoon.
** Homemade Air Thermometer [152]
The illustration shows the complete thermometer. The water in the
glass tube is caused to rise and fall by the expansion and
contraction of the air in the tin box. A paper-fastener box, about
1-1/4 in.
[Illustration: Air Thermometer]
deep and 2 in. in diameter will serve very well for the box A.
Solder in the side of the box 1-in. piece of 1/4-in. brass tubing,
B, and then solder on the cover, C, so that the only escape for
the air is through the brass tube. Secure a piece of 1/4-in. glass
tubing - not shorter than 18 in.--and bend it as shown at D in the
sketch. Hold the part of the tube to be bent in the broad side of
a gas jet, and in a minute or two the tube will bend with its own
weight.
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