Spherical Conductor, 8cm Diameter Subcategory_Sound and Resonance Designed to make electric field

Designed to make electric field lines visible

configured to make and break a circuit at the rhythm of a Morse-code transmission for telegraph-history demonstrations

set in motion by ion wind from corona discharge whenever the apparatus is connected to a high-voltage source

Five ceramic ring magnets at 1

Rectangular casted metal case and polythene insulated lid with finger flap to facilitate removal & front glass window

Spherical Conductor, 8cm Diameter Subcategory_Sound and Resonance Designed to make electric fieldPolished 8cm brass sphere on an ebonite insulated metal base, sized to retain induced charge through demonstrations of Coulomb's law and surface charge distribution.