Spectroscope
date: label: date made
content: late 19th century
notes: label: Description
content: This is a simple three-armed brass spectroscope with one glass prism, on a black iron tri-leg base. It was used by William Francis Hillebrand (1853-1925), an American chemist with a PhD from the University of Heidelberg who analyzed a vast array of mineral samples for the U.S. Geological Survey. In 1890, Hillebrand found that when crushed uraninite was dissolved in sulfuric acid, this uranium-bearing rock emitted a gas that he and his colleague William Hallock identified as nitrogen. When the British chemist, William Ramsay, analyzed similar rocks in 1895, he attributed the spectral lines to argon. William Crookes, however, realized that some of the lines were caused by helium, a substance hitherto found only in the sun. That meant that this instrument captured the first evidence of terrestrial helium.
label: Description
content: Ref. F. W. Clarke, “Biographical Memoir of William Francis Hillebrand,” <i>National Academy of Sciences Biographical Memoirs</i> 12 (1925): 43-70.
label: Location
content: Currently not on view
topic: label: Subject
content: Science & Scientific Instruments
setName: label: See more items in
content: Medicine and Science: Physical Sciences
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content: Science & Mathematics
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content: Optics
creditLine: label: Credit Line
content: U.S. Geological Survey
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: PH.326657
label: catalog number
content: 326657
label: accession number
content: 259238
objectType: label: Object Name
content: spectroscope
physicalDescription: label: Measurements
content: overall: 10 1/2 in; 26.67 cm
label: Measurements
content: overall: 10 5/8 in x 11 1/2 in x 11 5/8 in; 26.9875 cm x 29.21 cm x 29.5275 cm