Spiral rotary discharge tubes
notes: label: Description (Brief)
content: Spiral Rotary Discharge Apparatus. Brass trileg ring with a center glass column and seven glass tubes around perimeter. Base ring with three turned legs and braces to center. Center column solid glass 7/8" diameter, brass ferrule each end, upper has 1" diameter. brass sphere and removable spike 3.75" long, overall 14.75" long, seven tubes, 11/16' outside diameter, spiral foil inside each, brass ferrules each end, upper has sphere 3/4" diameter, overall 15" long. One glass tube is broken off and missing (only the base cup with a glass shard remains), and a replacement has been made and set in place. One other tube is broken near the top although pieces do not seem to be missing. The original rotor is missing and a replacement has been installed.
label: Description (Brief)
content: The hook on the center column connects to an electrostatic machine. As the machine generates a charge, the user sets the top rotor spinning. As the rotor approaches each grounded outer column, it is attracted to the brass cap which has an opposite charge. When the rotor and the cap are in close proximity, a spark jumps from the rotor to the cap. Now charged alike, the cap repels the rotor, moving it toward the next column. The electrical charge runs through the foil tape in the outer column toward ground, creating flashes of light at each narrow point on the tape. The base ring conducts the electricity to ground, returning the outer columns to an opposite charge before the rotor approaches the next column to repeat the discharge process.
setName: label: See more items in
content: Work and Industry: Electricity
label: Exhibition
content: The Electric Dr. Franklin
label: Exhibition Location
content: National Museum of American History
creditLine: label: Credit Line
content: from Mount St. Mary's College, thru Professor John W. Richards
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.326116
label: catalog number
content: 326116
label: accession number
content: 257245
objectType: label: Object Name
content: Spiral Rotary Discharge Apparatus
label: Object Name
content: electrostatic device
label: Object Name
content: electrostatic discharge apparatus
physicalDescription: label: Measurements
content: overall: 17 in x 12 1/2 in; 43.18 cm x 31.75 cm