» Glass sphere for electrostatic machine (0689)
Immagini
![Tratto da Rif. [1]](/foto/0689/0689_s2.png "Immagine: 1 - Tratto da Rif. [1]")
DESCRIPTION
Exhibit 689 is a glass sphere which was probably mounted on an electrostatic machine charged by rubbing. We have no trace of such a machine. The sphere has two supports: on one side a hub and on the other a pulley shaped for a circular leather belt that transmits rotation. On the inside there is a pith ball.
The hypothesis that this sphere was part of an electrostatic machine is suggested by the description and figure published by Francis Hauksbee (1660-1713) [2]. By rubbing the rotating sphere with a dry cloth or brush, one accumulated static electricity that could lead to a spark when approached.
BIBLIOGRAPHY
- [1] "Esperienze Fisico meccaniche sopra varj soggetti" opera di F. Hauksbee della Società Regia tradotta dall'idioma inglese - In Firenze M DCC XVI
- [2] URL [ http://en.wikipedia.org/wiki/Francis_Hauksbee ]
Dati Catalografici
| Data di costruzione: | Inizio XIX Secolo |
|---|---|
| Data di carico: | 1835-05-25 |
| Nr. Inventario: | 360 (Antico inv. Gabinetto Fis) |
| Costruttore: | Sconosciuta |
| Materiale: | vetro, ottone, sambuco |
| Dimensioni: | Diametro della sfera: 20 cm; Lunghezza totale (compresi i supporti): 35 cm |
| Conservazione: | buono (Manca l'apparato cui la sfera era collegata) |