Antique Sextant's

Welcome to the Antique Sextant website. 

We specialise in genuine antique marine navigation instruments: 

Sextant's, Octant's, Quintant's, Ship and Yacht Compass, Ship's logs, Station pointers, Pelorus, Chart instruments etc. We carry a large selection of top quality antique marine navigational instruments.

Tel: 01736 794383 - Mobile: 07977 116608

Antique sextant's and Octant's are very desirable and collectable maritime instruments, they are also a symbol of seafarers who have navigated the worlds oceans by using only the Sun, Stars and Moon for fixing a position. The primary use of a navigation Sextant or Octant is to determine the angle between an astronomical object and the horizon for the purposes of celestial navigation. The angle and time can be used to calculate a position line on a nautical chart. Common uses of the Sextant include sighting the sun at solar noon to determine latitude.

The Sextant was invented by Admiral John Campbell in 1757 after he discovered that the Octant was unable to measure angles large enough for Lunar distances ( Distance between Moon, Sun or Stars ) so he increased the 90 degree angle of the Octant to 120 degrees which formed the Sextant. He then engaged the nautical instrument maker John Bird to construct the first Sextant in 1759.

The Sextant gets its name from the Latin word for 'a sixth' because it is a sixth of a circle (60 degrees) and can measures angles of up to 120 degrees.

The Quintant is similar to the more common and well known Sextant, it is used in the same way but the Quintant has the ability to measure larger angles than the Sextant.

The Quintant gets it's name from the Latin word for 'a fifth' because it has an arc equivalent to one-fifth of a circle (72 degrees). Due to the doubling effect of the two mirrors this means it can measure angles of up to 144 degrees.

The Octant preceeded the design of the Sextant and it was invented by John Hadley and Thomas Godfrey simultaneously in 1731.

The Octant gets its name from the Latin word for 'a eighth' because it is an eighth of a circle (45 degrees) and can measures angles of up to 90 degrees.

In the early days the instrument frames were made from wood, usually Ebony with Ivory scales, however in the later years of Octant production the frames were made from brass and the scales were either Ivory or silver. 

This Antique Sextant website is part of the CLIPPER MARITIME ANTIQUES group.

We have been buying and selling maritime antiques & nautical collectables for over 30 years.