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Optical instrument for measuring the angle between a heavenly body and the horizon to determine the ship’s position.

See sextant in : french | spanish

Thumbnail for turning the micrometer screw.

Colored glass that blocks certain rays in the light spectrum to filter out ambient light.

Screw with a head graduated in minutes that is turned to set the index arm precisely.

Small graduated rule that slides along the ruler and is used to read very precise measurements.

Arc graduated in degrees; the observed angle measurement is read from it.

Support for the various components of the sextant.

Fixed mirror in front of the telescope; it is aimed at the horizon and the image of the Sun is projected on it.

Colored glass that blocks certain rays in the light spectrum to filter out ambient light.

Optical instrument that magnifies an observed object.

Device attached to the telescope’s eyepiece that shields the eye from light coming from the source and from strong ambient light.

Moving arm on the sextant that measures the displacement angle on the graduated arc to determine the height of the observed heavenly body.

Mirror integrated with the index arm that is positioned so that the Sun reflects on the horizon mirror.

Guide mark that helps to read the graduation marks on the arc.