electrophorus
Datecirca 1850
Inventory NumberDW0413
ClassificationElectrophorus
Subject
Maker
French
?
Cultural Region
Dimensions17.5 × 10 × 10 cm (6 7/8 × 3 15/16 × 3 15/16 in.)
Material
DescriptionThis object has several components. The base is a thin pewter disc. A shiny brass cylinder is mounted exactly in the center. Out of this emerges, straight up, a tall glass rod, barely rounded at the top.
Signedunsigned
FunctionThis component would have been stacked atop two other discs (one made of rubber and one of metal - see for example, 0503b and 0503c) in order to generate electricity by means of electrostatic induction.
To create electricity, the user would "evenly" rub this component with a cloth, often made of cat's skin. The negative charge produced by the friction of the second disc, induces a positive charge on the part of this component in contact with it (the bottom of this component) and a negative charge on the part furthest from it (the top of it).
In this condition, if this component is raised from the second disc by means of its glass insulating handle, no electrical effects will be noticed since the two opposite and equal charges unite and neutralize each other. If, however, this component is first touched by the user's finger and then raised from the second disc it will be found positively charged.
This charge can then be transferred to a Leyden jar, etc. This instrument was popular at least in part because it was a reliable and easy-to-use source of charge and voltage for experimental researches in electrostatics.
To create electricity, the user would "evenly" rub this component with a cloth, often made of cat's skin. The negative charge produced by the friction of the second disc, induces a positive charge on the part of this component in contact with it (the bottom of this component) and a negative charge on the part furthest from it (the top of it).
In this condition, if this component is raised from the second disc by means of its glass insulating handle, no electrical effects will be noticed since the two opposite and equal charges unite and neutralize each other. If, however, this component is first touched by the user's finger and then raised from the second disc it will be found positively charged.
This charge can then be transferred to a Leyden jar, etc. This instrument was popular at least in part because it was a reliable and easy-to-use source of charge and voltage for experimental researches in electrostatics.
ProvenanceDavid Wheatland purchased from Roux-Devillas Paris, June 6, 1969 (lot 10/6).
