Electric ... Ben Franklin   Wonder how the weatherman is able to
tell you if it's hot or cold outside? Chances are he or she uses
an instrument called a thermometer. It is a special instrument
that is able to measure heat in the air. To be your own
weatherperson you're going to need a thermometer. So let's make
one.   You'll need these materials to make a thermometer:     1.
Pour equal parts of tap water and rubbing alcohol into the
bottle, filling it about 1/8 of the way up.   2. Add a few drops
of food coloring to the mixture and stir or swirl the bottle to
mix.   3. Place the straw in the bottle but don't let it touch
the bottom of the bottle.   4. Seal the neck of the bottle with
modeling clay so that the straw stands upright. Hold your hands
on the bottle, and watch what happens to the liquid inside the
straw.  How It Works  The alcohol in the mixture heats up when
you place your hands around the bottle. Once the alcohol has
heated up, it starts to expand (get bigger) and has nowhere else
to go but up in