This glass tube was not so much made to demonstrate a physical problem, but was mainly for amusement. The hollow glass tube has diamonds of tin foil at the outside in the form of a spiral. The corners of the tin foil are close to each other. When an electrostatic generator is connected to the ends of the tube, the voltage will increase eventually to the point that sparks will spring simultaneously between the corners of the pieces of foil.
Straight flicker tube
circa 1850 - 1874