Abney Level
name: label: maker
content: Keuffel & Esser Co.
notes: label: Description
content: William de Wiveleslie Abney (1843–1920), an English scientist who made many important contributions to spectroscopy and photography, devised this type of level in the 1870s while working for the School of Military Engineering at Chatham.
label: Description
content: The inscriptions on this example read "KEUFFEL & ESSER CO. N.Y." and "29349." The vertical arc is marked "PERCENT" and graduated from 0 to 150 in both directions. Although the reference must be to percent of grade, the graduations are not regular, and their meaning is not yet understood. Keuffel & Esser described this as a Topographic Abney Level, "as made by us for the U.S. Forest Service." New, it cost $28.
label: Description
content: Ref: Keuffel & Esser, <i>Catalogue</i> (New York, 1921), p. 365.
label: Description
content: C. Jones, "Sir William de Wiveleslie Abney, K.C.B., D.C.L., D.Sc., F.R.S., Hon. F.R.P.S., etc.," <i>The Photographic Journal</i> 61 (1921): 296–311.
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
creditLine: label: Credit Line
content: LaVerne Watkins
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1989.0403.12
label: accession number
content: 1989.0403
label: catalog number
content: 1989.0403.12
objectType: label: Object Name
content: Abney level
physicalDescription: label: Measurements
content: case: 6 3/4 in x 3 1/4 in x 1 1/2 in; 17.145 cm x 8.255 cm x 3.81 cm
label: Measurements
content: level: 6 1/2 in; 16.51 cm
label: Measurements
content: arc: 3 1/2 in; 8.89 cm
label: Measurements
content: overall in case: 6 13/16 in x 3 1/4 in x 1 5/8 in; 17.30375 cm x 8.255 cm x 4.1275 cm