Polarizing Solar Eyepiece
date: label: date made
content: late 1880s
name: label: maker
content: Brashear, John A.
notes: label: Description
content: Several sorts of solar eyepieces came into use in the second half of the nineteenth century. This example, from the U.S. Naval Observatory, is based on the polarizing form produced by Merz in Munich; an account and illustration of that German instrument can be seen in <i>The Sun</i> (1880) written by the American astronomer, Charles A. Young.
label: Description
content: The “John A. Brashear / Allegheny, Pa. No. 16” inscription is that of John A. Brashear (1840-1920), a Pennsylvania machinist who moved to Allegheny in 1886, and who showed “a modification of the Merz-Young polarizing helioscope, less liable to breakage than the old form” at the 1887 meeting of the American Association for the Advancement of Science. The firm became The John A. Brashear Co., Ltd. in 1901.
label: Description
content: Ref: Len Jensen, “Two Rare Solar Eyepieces,” <i>Journal of the Antique Telescope Society</i> 2 (1992): 3-5.
label: Description
content: “Proceedings of the American Association,” <i>Science</i> 10 (1887): 85.
label: Location
content: Currently not on view
place: label: place made
content: United States: Pennsylvania, Pittsburgh, Allegheny City
topic: label: Subject
content: Science & Scientific Instruments
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: PH.327704
label: accession number
content: 283654
label: catalog number
content: 327704
objectType: label: Object Name
content: eyepiece, telescope
physicalDescription: label: Measurements
content: overall: 3 3/4 in x 3 5/8 in x 7 1/4 in; 9.525 cm x 9.2075 cm x 18.415 cm