This unit allows you to easily recreate Lord Kelvin's famous electrostatics experiment, in which an electrical current is induced by the breaking apart of water droplets. After a cascading separation of charges, an extremely high potential is reached causing a faint arc at the break in the wire (30kV/cm). Current then travels through the wires of the unit, to light the neon lamp (70V). The best gap is between 2 and 6 mm (6000 to 18000V).
Instructions available. Discussion of Millikan's experiments and Coulomb's Law are presented as Follow-Up Material, for more advanced students.
You will need to ground one of the cans to something metal. Expect a flash about once every 3 to 5 seconds.