The sextant is an instrument that allows measurements on celestial objects in relation to the horizon, which provides excellent results when it comes to finding the latitude of the ship. The sextant allows direct observation of the stars, so its use is possible 24 hours a day. For solar observations, the sextant is provided with filters that protect the view of its radiations. The horizon and the celestial object always remain stable, even when the user is on a mobile boat. This happens because the sextant sees the horizon directly, and sees the celestial objects by means of two opposite mirrors that cushion the possible displacements of the sextant due to the movements of the ship caused by the waves. The scale of a sextant has a length of one sixth circle full (60 °); hence the name of the sextant. If the scale is one eighth then the instrument is called Octant.
Isaac Newton (1643-1727) was the first to invent the principle of double reflection on which this instrument of navigation is based, however he never published it. Two more researchers, working separately, developed the octant around 1730: John Hadley (1682-1744), an English mathematician, and Thomas Godfrey (1704-1749), a Philadelphia glassmaker
In Antiquus, we have two types of presentation as you can see in the photographs. The first is a compact embossed leather case, the second case is also made of leather but it has a glass window. Any of them is a perfect presentation for the object. If you had a special preference, please indicate it in the section "observations" when you go to place the order, otherwise we will understand that any of them is valid.
A small brochure is also sent with the history and the principles of its operation as we indicate where in iNTERNET to learn how to handle it. Here I found a curious video that was filmed aboard the Fifth Royal at the end of May 2016. It is explained with a real example how the calculation of the distance to a point on the coast is made by observing the height of a reference represented in the letter measured with the sextant.
We hope you have been very helpful this post.
Sources: Antiquus, aytolacoruna, nautic school Navarra