A galvanometer is an instrument that detects electrical current. You can easily make one at home with items you may have lying around your house. All you need is a match box (or other small box) that is large enough to house a compass, a compass, tinfoil, and a D battery.
Begin by cutting 1 yard of tin foil.
Next, fold it repeatedly until you have a narrow strip of tinfoil.
Place the compass in the box and wrap the tinfoil strip around the box several times. Let the ends hang from the box.
Take the ends and connect to the terminals of a D battery. Watch the needle of the compass move. The battery emits electrons that run through the aluminum foil (your conductor). When electrons move they create a magnetic field which moves the compass needle.