Sextant: a navigation instrument that is used to establish position by measuring the height of stars from the horizon.
Index mirror: large polished plate that reflects light.
Telescope: optical instrument made of lens that magnifies objects.
Telescope clamp: reinforcing circle.
Eyepiece: lens the user looks through.
Telescope printing: lens adjustment.
Frame: structure that serves as the base for the different parts of the sextant.
Graduated arc: graduated edge of the arc.
Locking device: apparatus that holds the sextant in place.
Drum: graduated button used to take measurements.
Index arm: type of ruler that determines direction or measures an angle.
Screw to regulate small mirror: piece of metal used to adjust the horizon mirror.
Glass filter: colored transparent substance.
Horizon mirror: small polished glass plate that reflects light.
Glass filter: colored transparent substance.