Globe-type Electrostatic Machine
Globe-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 ½ scale-model of Benjamin Franklin’s electrostatic generator was made in 1897 in the Smithsonian’s model shop based on drawings of a machine at the Franklin Institute in Philadelphia. Their machine “was received by the Franklin Institute from Dr. J. Redmond Coxe in 1826 who said that the machine had belonged to Franklin himself.” Smithsonian curator George C. Maynard paid $25 for drawings of the Franklin Institute’s machine and then displayed this model at the 1897 Nashville Exposition.
- Early electrostatic machines generated a charge by spinning a globe against a pad. The charge could then be used directly in experiments or transferred from the globe to a Leyden jar. This model differs somewhat from the Franklin-style machine collected over a half century later (catalog #EM*325513) but shows the basic design of a rotating glass globe, leather rubbing pad and brass charge collector. The Smithsonian preserves many authentic pieces of the past but occasionally uses reproductions and models when original objects no longer exist or would be impossible to display.
- Location
- Currently not on view
- date made
- 1897-05-25
- date loaned
- 1897-06-04
- maker
- Model Shop, United States National Museum
- Physical Description
- wood (overall material)
- glass (overall material)
- brass (overall material)
- Measurements
- overall: 84.5 cm x 30.8 cm x 39.4 cm; 33 1/4 in x 12 1/8 in x 15 1/2 in
- ID Number
- EM.181501
- catalog number
- 181501
- nonaccession number
- 1987.3093
- See more items in
- Work and Industry: Electricity
- Science & Mathematics
- Electrostatic Machines
- Data Source
- National Museum of American History
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