Dynameter
date: label: date made
content: 1870s
name: label: maker
content: Kahler, Edward
notes: label: Description
content: This seems to be the Ramsden dynameter made in the early 1870s for use with the new 26-inch equatorial refractor at the U.S. Naval Observatory. Its purpose was to determine the magnifying power of the various eyepieces. The “Edwd Kahler, Washn D.C.” inscription refers to Edward Kahler (1833-1890), an optical and mathematical instrument maker from Germany who was working in Washington, D.C. by 1869.
label: Description
content: Ref: Humphry Lloyd, <i>A Treatise on Light and Vision</i> (London, 1831), p. 305.
label: Description
content: <i>Astronomical and Meteorological Observations Made During the Year 1874 at the United States Naval Observatory</i> (Washington, D.C., 1877), p. 38.
label: Description
content: “Report of Professor Hall,” (p. 12) in <i>Reports of Observations of the Transit of Mercury, May 5-6, 1878</i> (Washington, D.C., 1879).
label: Location
content: Currently not on view
place: label: place made
content: United States: District of Columbia
setName: label: See more items in
content: Medicine and Science: Physical Sciences
creditLine: label: Credit Line
content: U. S. Naval Observatory
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 2005.0172.16
label: accession number
content: 2005.0172
label: catalog number
content: 2005.0172.16
objectType: label: Object Name
content: dynameter
physicalDescription: label: Measurements
content: overall: 3 in x 9 in x 5 1/4 in; 7.62 cm x 22.86 cm x 13.335 cm
label: Measurements
content: overall in box: 3 5/8 in x 9 1/2 in x 5 1/8 in; 9.2075 cm x 24.13 cm x 13.0175 cm