electrophorus
Date1850-1900
Inventory Number1997-1-0650
ClassificationElectrophorus
Subject
Maker
American
?
Cultural Region
Dimensions12.5 × 14.6 × 14.6 cm (4 15/16 × 5 3/4 × 5 3/4 in.)
Material
DescriptionThe electrophorus has several components. The base is a thin metal disc. Mounted exactly in the middle is a cylindrical brass component that looks much like the base for a candlestick, except smaller and stouter. Out of this cylindrical portion of the base emerges a tall rod, made of a dark rubber, which is lipped at the bottom and tapers out as it rises. At the top it is barely rounded.
Signedunsigned
Curatorial RemarksIdentical to 1997-1-0651.
FunctionThe electrophorus is a simple device for generating static electricity. 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.
This 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 "brutely" rub this component with a cloth, often made of cat's skin. The negative charge produced by friction with the second disc, induces a positive charge on the part of this component in contact with the second disc (the bottom of this component) and a negative charge on the part furthest from it (the top of this component).
In this condition, if this component is raised from the second disc by means of its 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.
This 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 "brutely" rub this component with a cloth, often made of cat's skin. The negative charge produced by friction with the second disc, induces a positive charge on the part of this component in contact with the second disc (the bottom of this component) and a negative charge on the part furthest from it (the top of this component).
In this condition, if this component is raised from the second disc by means of its 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.
American
Date: 1870-1930
Accessories: small rubber hose; tiny metal clamp-like component
Object number: 1996-1-0426
The W. M. Welch Scientific Company
Date: 1910-1940
Object number: 1996-1-0484