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.

Ref. F. W. Clarke, “Biographical Memoir of William Francis Hillebrand,” National Academy of Sciences Biographical Memoirs 12 (1925): 43-70.

Date Made: late 19th century

Location: Currently not on view

Subject: Science & Scientific Instruments


See more items in: Medicine and Science: Physical Sciences, Science & Mathematics, Optics


Exhibition Location:

Credit Line: U.S. Geological Survey

Data Source: National Museum of American History

Id Number: PH.326657Catalog Number: 326657Accession Number: 259238

Object Name: spectroscope

Measurements: overall: 10 1/2 in; 26.67 cmoverall: 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

Guid: http://n2t.net/ark:/65665/ng49ca746ae-2202-704b-e053-15f76fa0b4fa

Record Id: nmah_1463296

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