Pyxis, the Instrument that Changed the World

15 March 2022

Pyxis may be small and faint, but what a mighty instrument its line of three fourth magnitude stars represent – the mariner’s compass. Prior to the invention of the compass it was better to be a penguin than a seafaring navigator. Sailors relied on the sun or stars, but put humans in a deep fog and they go in circles, hopelessly lost. Getting hopelessly lost in treacherous seas in a deep fog was a terrible danger, often with disastrous consequences. On the other hand, Fiordland penguins, found in the waters of Antarctica around the Southern Islands, navigate treacherous seas safely up to 6,800km on the round trip from their breeding site in New Zealand. 

Although the history of the compass started more than 2000 years ago during the Han dynasty (202 BC – 220 AD), it was not used for navigation, but for geomancy and fortune-telling by the Chinese. The first reference to the use of the compass in navigation was by the Chinese around AD 1100 in the book, Phing-Chou Kho T’an, which included information about sailing ships and customs at sea.  The so-called “south-pointing fish” was a wooden fish with a magnetized iron needle within it, that floated in a bowl of water. (The south was the preferred direction of the Taoist trigrams. It was the direction of the sky, while the north was considered inauspicious.) Later, a dry compass version evolved in the shape of a turtle. Lodestone was embedded in its carved wooden body and balanced on a bamboo needle, which allowed it to rotate freely.

Alexander Neckam (1157-1217), an English theologian and poet, produced the earliest European account of the compass. In his De utensilibus (On instruments, 1190) he noted how a ship, among its other stores, must have a needle placed above a magnet (mounted on a pivot), which would revolve until its point looked north, and guide sailors in murky weather or on starless nights. 

Without the invention of the compass, we wouldn’t have had the Age of Discovery which yielded unprecedented discoveries between the 1400s and 1600s and forged interactions between Europe, Asia, and the New World that forever altered the course of history. 

As a child in the 1960s a compass played an enormous part in my childhood age of discovery… my father took us children on wonderful adventures into the most remote parts of  Mozambique, navigating by his trusty compass. I can remember when I learnt how to navigate with a compass. I was eight years old and my father took my brother and I on a hell of a trek through the mangrove swamps and tidal flats in Sofala Mozambique to find the ruins of a 16th century Portuguese fort. He taught me how to navigate using his compass and all these decades later I can still remember the thrill and awe of holding in my hand the little device that always pointed north. 

All that remains of the fort are these crumbling stone remnants, ravaged by sea, sand, wind and time and disappearing into a shifting sandbar…

When Lacaille split the huge and magnificent ship Argo Navis into Carina, Puppis  and Vela, he appropriated the stars that had been catalogued by Ptolemy as lying in the mast of the ship and invented Pyxis. However, Pyxis isn’t part of the dismantled ship; Lacaille showed it separately from Argo on his map and in his catalogue. His original depiction of it was published in 1756 under the French name la Boussole, and in the notes accompanying the chart he described it as ‘le Compas de mer’. On the second edition of his chart in 1763 Lacaille Latinized its name to Pixis Nautica (sic), which was subsequently shortened, with amended spelling, to just Pyxis. (Interestingly, in 1844 John Herschel suggested renaming Pyxis as Malus, the Mast, which would have returned the stars to the dismantled ship but the new name, thank goodness, was never accepted.)

Small, faint and seemingly insignificant these few stars symbolize a truly historic instrument that changed the world and holds so much meaning and significance for many different reasons. And one can never get lost literally or figuratively with a compass at hand. 

Observing Pyxis

16″ f/5 Dobs; 150x, 228x and 333x