{
  "name": "Nautical mile definitions and values, 1894 to 1959",
  "desc": "U.S., British Admiralty and international nautical miles as printed in U.S. government sources, with body and year, plus two values computed here (the British mile in meters and the old U.S. mile recomputed from its 1894 definition). One claim per row.",
  "lic": "CC BY 4.0",
  "lic_url": "https://creativecommons.org/licenses/by/4.0/",
  "by": "The Yardstick Almanac",
  "url": "https://theyardstickalmanac.com/units/nautical-mile/",
  "from": [
    "NBS Special Publication 447, Appendix 3 (U.S. conversion tables of March 21, 1894) and Appendix 4 (NBS Technical News Bulletin, August 1954): U.S. nautical mile 1,853.248 m (6,080.20 ft); British Admiralty 6,080 British feet",
    "Federal Register 24 FR 5348 (1959) and NIST Handbook 44 (2026), Appendix C, note 21: 1852 m = 6,076.11549 international feet (approximately); effective July 1, 1954 in the U.S. Commerce and Defense departments",
    "BIPM, The International System of Units (SI Brochure), 9th edition, V4.01 (June 2026), Table 8 and note (k): 1 nautical mile = 1852 m; 1 knot = (1852/3600) m/s",
    "PROJ 9.8.1, src/ellps.cpp: WGS 84 a = 6378137.0 m, 1/f = 298.257223563 (corresponding to NGA TR8350.2); Clarke 1866 a = 6378206.4 m, b = 6356583.8 m"
  ],
  "how": "Compiled by The Yardstick Almanac from the data listed",
  "data_by": [
    "Values from U.S. government publications (NBS SP 447, NIST Handbook 44, NIST SP 811, 24 FR 5348; public domain) and the BIPM SI Brochure, 9th ed. V4.01 (CC BY 4.0; adapted: values restated, not the table); compiled and partly computed 2026-11-01, CC BY 4.0"
  ]
}