» Cavendish hemispheres (0025)
Immagini
DESCRIPTION
Exhibits 25, 26 and 40 are Cavendish hemispheres utilized to demonstrate that electrical charge brought onto an isolated conductor will always be distributed on the external surface. Besides the copper Cavendish hemispheres with their insulated handles, the set includes a Cavendish sphere on an insulated support (exhibit 40) an electroscope and an electrostatic generator (such as a hard rubber rod and a wool cloth).The demonstration starts by electrifying the sphere and assuring that the hemispheres are uncharged. Then the hemispheres are carefully placed around the sphere allowing the sphere support to pass through the provided cuts in the hemisphere edges. Then the hemispheres are allowed to touch the sphere and then withdrawn. Successive measurements with the electroscope then verify that the hemispheres are charged and the sphere is not. When the hemispheres touch the enclosed sphere the charge flows to the external surface provided by the hemispheres.
Dati Catalografici
| Data di costruzione: | anteriore al 1835 |
|---|---|
| Data di carico: | 1835-05-25 |
| Nr. Inventario: | 717 (Generale dal 1874) 287 (Antico inv. Gabinetto Fis) |
| Costruttore: | Costruttore sconosciuto |
| Materiale: | ottone, vetro |
| Dimensioni: | Diametro: 11 cm; Manici: 29 cm |
| Conservazione: | ottimo |