A tube of glass around which is pasted a series of tinfoil circles,
diamonds, or little squares, or other form of interrupted conductor. The
pieces generally are placed in the line of a spiral. When a static
discharge of electricity takes place along the conductor a row of bright
sparks is produced at the breaks in the conductor. These by reflection
are multiplied apparently, and a beautiful effect of intersecting or
crossing spirals of sparks is presented.

The experiment is in line with the luminous pane and lightning jar, and
is used merely as a demonstration, or lecture experiment.

Synonym–Luminous Tube.