This reproduction sextant comes in its own leather carrying/storage case. A sextant is a doubly reflecting navigation instrument that was used to measure the angular distance between two visible objects.
The primary use of a sextant was to measure the angle between an astronomical object and the horizon for the purposes of celestial navigation. The estimation of this angle and the time when it was measured can be used to calculate a position line on a nautical or aeronautical chart—for example, sighting the Sun at noon or Polaris at night (in the Northern Hemisphere) to estimate latitude. Sighting the height of a landmark can give a measure of distance off and, held horizontally, a sextant can measure angles between objects for a position on a chart.
Size: the instrument measures approximately 12 x 13 cm (4.72 x 5.12 inches) and comes in a 8 x 15 x 15.5 cm (3.15 x 5.91 x 6.10 inches) genuine leather box.