Rowland condenser for ratio of charge
date: label: date made
content: 1889
name: label: associated person
content: Rowland, Henry Augustus
label: maker
content: Grunow, William
notes: label: Description (Brief)
content: Condenser for determining the ratio of electromagnetic to electrostatic units. Designed by Henry A. Rowland. Large brass sphere mounted on wooden base with scale and counterbalance weight. The inscription on a brass plate of this device reads “Wm. Grunow / New York.” Henry A. Rowland, professor of physics at Johns Hopkins University, explained that “This very accurate instrument was made from my designs by Mr. Grunow, then of New York, and consisted of one hollow ball, very accurately turned and nickel plated, in which two balls of different sizes could be hung by a silk cord.” Rowland also noted that “A further description is given in Mr. Rosa’s paper.”
label: Description (Brief)
content: References: Henry A. Rowland, with the assistance of E. B. Hall and L. B. Fletcher, “On the Ratio of the Electromagnetic to the Electrostatic Unit of Electricity,” Philosophical Magazine 87 (1889): 304-315. Edward B. Rosa, “Determination of v, the Ratio of the Electromagnetic to the Electrostatic Unit,” Philosophical Magazine 28 (1889): 315-332. E. B. Rosa and N. E. Dorsey, “A New Determination of the Ratio of the Electromagnetic to the Electrostatic Unit of Electricity,” Bulletin of the Bureau of Standards 3 (1907): 435-604, on 439-441. Rosa was a physics student at JHU.
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
creditLine: label: Credit Line
content: from Johns Hopkins University, thru G. A. Dieke
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.318513
label: catalog number
content: 318513
label: accession number
content: 235069
objectType: label: Object Name
content: Condenser
label: Object Name
content: condenser
label: Object Name
content: capacitor
label: Other Terms
content: Condenser; Electrostatic Devices
physicalDescription: label: Measurements
content: overall: 26 in x 20 in x 15 7/8 in; 66.04 cm x 50.8 cm x 40.3225 cm