The tank is placed with the partition
directly under a water tap and the flow of water will cause it to
tip from time to time, keeping the prints constantly moving about
in the water.
** Home-Made Soldering Clamps [137]
Take a cotter pin and bend it over a small rod to bring the points
together, as shown in the sketch. This will make a spring clamp
that is opened to slip over the articles to be clamped together by
inserting a scratch awl or scriber between the legs at the bowed
portion. To make a more positive clamp before bending the legs to
a bow, slip a short coil of wire over the pin, passing it down to
the ring end. Wire 1/32 in. in diameter wound over a wire slightly
larger in diameter than that of the cotter will do. In soldering,
smoke the legs well to avoid solder adhering to them. The clamp is
tightened by pushing up the coil ring toward the bow of the legs
and then twisting it like a nut, the coil being wound
right-handed, so that it will have a screw effect.
[Illustration: Clamp]
** A Telephone Experiment [137]
If the small apparatus, as shown in the accompanying sketch, is
attached to the under side of an ordinary dining table, it will,
if connected to a telephone circuit, set the table in vibration,
so that any number of people who put their ears flat upon the
table will hear the voice of a person speaking from a distance,
apparently coming out of the table, says the Model Engineer.
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