» Electrical Instrument Box (0009)

Immagini

DESCRIPTION

Exhibit 9 is an Electricity Demonstration Case. This set of tools used to carry out experiments of electrification on different materials consists of 18 rods, of different thickness and surface roughness. In particular, there are rods of sealing wax, of crystals, of various metals and a cat skin. These tools served to demonstrate how, rubbing rods of different material with the same skin, two kinds of electricity, vitreous and resinous, showed up. Vitreous was the charge obtained by rubbing glass; resinous by rubbing a resinous material. These two electric fluids were called later by Franklin positive and negative. Many treatises on physics of the nineteenth century carry lists of materials deemed vitreous or resinous depending on how they were electrified by rubbing; from the middle of the nineteenth century onward this distinction disappeared, and the various materials were put in an order such that the previous electrifies positively the next, if rubbed together.

The acquisition date is not recorded, but from the inventory number it can be deduced that it is around 1850. The box is not signed, but the stile is typical that of the Turin Manufacturer Jest. The inventory price was 4 Lire. On the red box is painted with large gold letters, "ElettricitÃ "

OBSERVATION

The inventory date is not recorded but from the number the period is around 1850.
The case is not signed but the style is that of Jest
It entered the inventory as: " wood case colored in vermilion for collecting and conserving glass cylinders, wax, etc."
Inventory price: 4 Lire

ISCRIZIONI

Sulla cassetta rossa è scritto in oro, a grandi caratteri, "Elettricità"

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