http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
with ancient and modern instruments of navigation
90 pages including frontispiece, illustrations, diagrams 22 cm
Old instruments -- Principles of the sextant -- Construction of the marine sextant -- The booth bubble -- Construction of air sextants -- Sextant telescopes -- Making observations by marine and air sextants -- Errors and adjustments of sextants -- Modern sextant accessories and navigational instruments.