Pyrheliometer
name: label: maker
content: Ducretet, Eugene Adrien
notes: label: Description
content: “Perhaps the best known instrument for measuring solar heat is one which ought to be considered, among those still in use, the worst in principle, and in practice one of the most untrustworthy. I refer to the pyrheliometer of Pouillet, which was the best attainable fifty years ago, and which is to be found described in every text-book on the subject.” So wrote Samuel Pierpont Langley, the director of the Allegheny Observatory, in his account of his 1881 expedition to Mount Whitney, to measuring solar radiation with his newly developed bolometer.
label: Description
content: Charles Greeley Abbot, Langley’s assistant and then successor at the Smithsonian Astrophysical Observatory, apparently thought more highly of pyrheliometers. This example came from the S.A.O. An inscription reads "E. Ducretet et L. Lejeune, a Paris."
label: Description
content: Eugene Adrien Ducretet (1844-1915) was a scientific instrument maker who, after an apprenticeship with Paul Gustav Froment, opened his own workshop in Paris in 1864. He performed some of the first experiments with wireless telegraphy (radio) in France. Leon Lejeune was his partner and son-in-law.
label: Description
content: Ref: S. P. Langley, <i>Researches on Solar Heat</i> (Washington, D.C., 1884), p. 51.
label: Description
content: Ref: E. Ducretet et L. Lejeune, Catalogue des Instruments de Precision (Paris, 1893).
label: Description
content: C. G. Abbot, “The Silver Disk Pyrheliometer,” <i>Smithsonian Miscellaneous Collections</i> (Washington, D.C., 1911).
label: Location
content: Currently not on view
setName: label: See more items in
content: Medicine and Science: Physical Sciences
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: PH.314878
label: catalog number
content: 314878
label: accession number
content: 211531
objectType: label: Object Name
content: pyrheliometer, pouillet
physicalDescription: label: Measurements
content: overall: 3 1/2 in x 20 3/8 in x 4 3/4 in; 8.89 cm x 51.7525 cm x 12.065 cm