Cylinder-type Electrostatic Machine
date: label: date made
content: ca 1840
name: label: maker
content: Palmer, E.
notes: label: Description (Brief)
content: People from ancient times knew that rubbing certain materials and then touching something caused a spark. Studying what is called electrostatics laid the groundwork for understanding electricity and magnetism. Natural philosophers, scientists, and instrument makers created many ingenious devices to generate electrostatic charges starting in the 1600s. These machines varied in size and technique but all involved rotary motion to generate a charge, and a means of transferring the charge to a storage device for use.
label: Description (Brief)
content: This machine was made in London by Edward Palmer (1803–1872) about 1840. The leather rubbing pad with a silk flap rides against one side of the cylinder and a brass prime conductor on the other side collects the charge with a brass comb. Both are mounted on insulating glass rods. A screw mechanism at the bottom adjusts the tension of the rubbing pad more precisely. During the 1750s electrical researchers refined the design of electrostatic machines by replacing earlier spherical globes with a glass cylinder, a design used for many years. This change increased the surface area of the glass in contact with the rubbing pad and improved the efficiency of the generator. Palmer sold microscopes and other scientific supplies from his shop on Newgate Street from about 1837 to about 1845 when he sold his business.
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
label: See more items in
content: Science & Mathematics
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content: Electrostatic Machines
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.319503
label: catalog number
content: 319503
label: accession number
content: 238500
objectType: label: Object Name
content: cylinder-type frictional electrostatic machine
label: Object Name
content: electrostatic generator
label: Other Terms
content: cylinder-type frictional electrostatic machine; Electrostatic Devices
physicalDescription: label: Physical Description
content: wood (overall material)
label: Physical Description
content: glass (overall material)
label: Physical Description
content: brass (overall material)
label: Physical Description
content: cloth (overall material)
label: Physical Description
content: steel (overall material)
label: Measurements
content: overall: 15 1/2 in x 19 1/2 in x 10 in; 39.37 cm x 49.53 cm x 25.4 cm