Spark or flicker tube. A glass tube with bulbous brass ends and a spiral of silver metal dots running along the inside.

ABDNP:201762a

Glass tube with brass ends; with ball terminals; inside tube is spiral of small metal discs each seperated by gap of less than 1 mm; when tube is placed across an electrostatic generator, a spiral discharge is seen around inside of tube caused by sparking between metal discs

1780-1810

glass, brass, metal
length 330 mm; diameter 25 mm

Physical Object