Historical information

When glass disc spins the line visible through the front slit shows the movement of waves - sound , light

Physical description

Wooden frame - solid front with window slit. Open back with wooden cross bar. Spinning glass disc with a continuous black circular line - varying widths. One red line in one section.

Inscriptions & markings

Metal plate on front " MADE SPECIALLY FOR H.B.SILBERBERG & CO MELBOURNE"