Cylinder-type Electrostatic Machine

Description (Brief)
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.
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.
Location
Currently not on view
Object Name
cylinder-type frictional electrostatic machine
electrostatic generator
date made
ca 1840
maker
Palmer, E.
Physical Description
wood (overall material)
glass (overall material)
brass (overall material)
cloth (overall material)
steel (overall material)
Measurements
overall: 15 1/2 in x 19 1/2 in x 10 in; 39.37 cm x 49.53 cm x 25.4 cm
ID Number
EM*319503
catalog number
319503
accession number
238500
See more items in
Work and Industry: Electricity
Science & Mathematics
Electrostatic Machines
Data Source
National Museum of American History, Kenneth E. Behring Center

Comments

Add a comment about this object