Reducing Arc
name: label: maker
content: A. Lietz Company
notes: label: Description
content: William T. Rhodes (1898-1961) invented the reducing arc while conducting a topographical survey through the rugged terrain along the Merced River in California, in preparation for the All Year Highway to the west entrance of Yosemite National Park. When his design proved practicable, Rhodes submitted a patent application and convinced Lietz to manufacture the device in exchange for royalties.
label: Description
content: The first advertisements appeared in 1928, and Rhodes received a patent in 1930. The Rhodes reducing arc was soon popular, especially with highway engineers. Lietz still had some in stock in the late 1980s. The inscription on this example reads "RHODES REDUCING ARC MFD. BY The A. LIETZ CO. SAN FRANCISCO, U.S.A. PATENTED NO. 1,785,284 SERIAL No. 18296."
label: Description
content: The Rhodes reducing arc consists of a semicircle attached to a vertical pole, with a sighting tube on the straight edge. With it, a surveyor can take a sight on a vertical range pole, use a tape to measure the slope distance to the pole, and read the horizontal and vertical distances on the gridded half of the arc.
label: Description
content: Ref: Doug Morin, "William T. Rhodes and His Reducing Arc," <i>P.O.B.</i> (May 1996): 60-64.
label: Description
content: A. Lietz, <i>Engineering, Surveying, Mining and Nautical Instruments</i> (San Francisco, 1928), pp.122-123.
label: Location
content: Currently not on view
setName: label: See more items in
content: Medicine and Science: Physical Sciences
label: See more items in
content: Surveying and Geodesy
label: See more items in
content: Measuring & Mapping
publisher: label: Related Publication
content: P.O.B.
label: Related Publication
content: A. Lietz. Engineering, Surveying, Mining and Nautical Instruments
creditLine: label: Credit Line
content: Michael Baker, Jr., Inc.
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1997.0290.07
label: accession number
content: 1997.0290
label: catalog number
content: 1997.0290.07
objectType: label: Object Name
content: reducing arc
physicalDescription: label: Measurements
content: overall: 15 in x 21 in x 2 1/2 in; 38.1 cm x 53.34 cm x 6.35 cm