Young & Sons Wye Level

This instrument is marked "Young & Sons, Philadelphia 5867" and dates from around 1875. The mark on the telescope-"Patented July 28th 1874"-refers to the patent (#153,494) granted to J. W. Nystrom and Alfred Young. It describes a method of regulating the focus of a telescope by moving the erecting lenses back and forth while keeping the object glass and cross hairs at a fixed distance from one another.
Currently not on view
Object Name
Young & Sons
telescope: 19 in; 48.26 cm
place made
United States: Pennsylvania, Philadelphia
ID Number
accession number
catalog number
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Medicine and Science: Physical Sciences
Measuring & Mapping
Surveying and Geodesy
Data Source
National Museum of American History, Kenneth E. Behring Center

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