Ritchie Liquid Compass
date: label: date made
content: 1873
name: label: maker
content: Ritchie, Edward S.
notes: label: Description
content: This compass–with six needles, and a flat card with central buoyancy–was Ritchie’s most successful design and was widely used by American merchant ships and the U.S. Navy. The Ritchie ledgers, now held by Ritchie Navigation, indicate that this example was manufactured on Jan. 5, 1873 and sold to one L. J. Sloane. The U.S. Coast & Geodetic Survey acquired it in 1914, and transferred it to the Smithsonian in 1929. The inscriptions read "E. S. RITCHIE BOSTON. PATENTED SEPT. 9, 1862. APL. 7, 1863. MAY 12, 1868. July 19, 1870" and "6937" and "U.S.C.&G.S."
label: Description
content: Ritchie’s patent of Sept. 9, 1862 (#36,422) described a liquid compass so designed that the liquid would not oxidize the magnet or card, and that the friction and wear of the pivot and its bearing was minimized. Ritchie obtained two patents on April 7, 1863. One (#38,125) described a needle enclosed in an air-tight metallic case; the other (#38,126) described a liquid compass that could be read at a distance so it would not be affected by any iron on or about the deck of a ship. Ritchie’s patent of May 12, 1868 (#77,763) described a paint that would not deteriorate in the liquid in the compass. His patent of July 19, 1870 (#105,492) described a way to hold the glass in place with a water-tight joint..
label: Description
content: Ref: E. S. Ritchie & Sons, <i>Ritchie’s Liquid Compasses and Nautical Instruments</i> (ca. 1905).
label: Description
content: T. S. & J. D. Negus, <i>Illustrated Catalogue of Nautical Instruments</i> (New York, n.d.), p. 204.
label: Location
content: Currently not on view
place: label: place made
content: United States: Massachusetts, Boston
setName: label: See more items in
content: Medicine and Science: Physical Sciences
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content: Navigation
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content: Measuring & Mapping
creditLine: label: Credit Line
content: U.S. Coast & Geodetic Survey
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: PH.309656
label: catalog number
content: 309656
label: accession number
content: 106954
objectType: label: Object Name
content: Nautical Compass (Liquid)
physicalDescription: label: Measurements
content: bowl: 7 1/2 in; 19.05 cm
label: Measurements
content: card: 6 1/2 in; 16.51 cm
label: Measurements
content: overall: 6 5/8 in x 11 5/8 in x 5 7/8 in; 16.8275 cm x 29.5275 cm x 14.9225 cm