A classic piece of nautical navigation, the sextant is an intricate and fascinating device that has been used since the eighteenth century to measure the altitude of celestial bodies, as well as horizontal and vertical angles and heights of shore objects.
From the origins of the first ever sextant to the evolution of the design that led to their beautiful construction, Sea Chest has put together a list of the most interesting facts to celebrate this iconic marine instrument - and who knows? Maybe you'll want to buy one for yourself!
#1. When translated from Latin it means "sixth part" because the shape of the instruments arc is one sixth of a circle. The term is also used to include other similar reflecting instruments such as the quadrant - used to measure angles up to 90 degrees - as well as the quadrant, quintant, and octant.
#2. Sextants can be used to measure the distance between the moon and other celestial bodies to determine Greenwich Mean Time (GMT).
#3. Unlike most modern navigation tools such as GPS, the sextant doesn't require any electrical power to function, meaning they still serve as a great reserve navigational tool on board ships to this day.
#4. Sextants are incredibly precise due to their clever construction - measuring celestial objects relative to the horizon and not the instrument itself.
#5. The first sextant was made in 1759 by John Bird, one of the most famous craftsman of mathematical instruments. His early sextant designs were made from a heavy mahogany and ivory construction before being streamlined later on by other instruments makers to lighter wooden frames, and then in the nineteenth century they were crafted from fine brass.
#6. Sextants can be used at night to observe the stars.
#7. To use a sextant correctly, navigators lift it using their left hand and then hold it in their right hand by the handle and look at the sea horizon.
#8. A sextant doesn't require that you use it with perfect aim, making the instrument incredibly effective on a moving vessel - both the horizon and the stars or planets will remain steady in their relative position.
#9. In hot and tropical climates, sextants were often painted white to reflect sunlight and stay cool, preventing a change in temperature from warping the frame or arc.
#10. Although heavy, the classic brass construction of a sextant means they are less susceptible to shaking when being used at sea compared to lighter materials.
Fancy taking a look at our very own range of sextants and celestial navigation books? Click here to see more!