14 September 2020

Razor’s Edge Precision in Transmision

We are so used to having international standard measures, printing machinery, and recording devices, that we lose sight of how many practical complications did arise when they did not exist. If you have a navigation instrument, which makes the difference between landfall and shipwreck, or the recipe for a medicine, which becomes deadly poison in an overdose, how do you ensure a fail-safe transmission of the necessary knowledge? The answer is simple: you only rely on direct transmission, “by word of mouth,” viva voce. Learning by the eye and by the hand has no substitute in practical arts. Nonetheless, those who know are driven to write ever-imperfect, intrinsecally flawed, or simply hopeful and well-meaning instructions for later generations.

In the context of Indian Ocean navigation, as mentioned last week, we know that it was not simply about an instrument or a set of instruments, but that a sophisticated system of combined and counterchecked observations came into play with the methods transmitted from pilot to pilot—also, symbolically, “from father to son,” as we had found earlier in Ibn Mājid. Last week we found in the Fawā’id a passing detail on the accurate usage of the altitude measuring instrument, the khashbah or “piece of wood” called kamāl in some specialised literature.
“When positioning the wood to make your measure, there must be a thread’s width between the wood and the star you are measuring, and also a thread, fine as a knife’s edge, between the wood and the horizon.”
Immediately after that, Ibn Majid dedicates a few lines to explaining the “intellectual” (‘aqlī) nature of early nautical science, which comes from “the time of the prophets.” The astrolabe comes up as a token of those times, and its invention is attributed to Lāb, son of Idrīs, the archaic and enigmatic prophet, originator of the crafts and identified with Enoch and with Hermes Trismegistus. Ibn Mājid dares not criticise this prophetic knowledge, but the import of his text is clear, and partly explicit: a person needs to have arrived safely ashore many times, and to have faced disaster, before engaging in any pompous discourse about nautical matters. Caveat nauta!

07 September 2020

The Lion’s Sneeze (al-Nathrah)

The eighth lunar mansion, according to Ibn Mājid’s count, is yet another one of the parts of the ancient Arab constellation called the Lion, al-Asad. This Lion was so big that it provided material for about eight lunar mansions. It has been dissected and studied in detail by our colleagues at Two Deserts: One Sky, who call it a megaconstellation which “roared from January to May.”

The mansion we are reading about now, al-Nathrah is formed by stars so dimly visible, that they were compared to the droplets of a sneeze. They include, notably, what we call the Beehive Cluster (aka Praesepe, or M44), located at the heart of our constellation of Cancer. M44 was noted in European astronomy since Late Antiquity as nebulosa in pectore Cancri, “a misty thing on the chest of the Crab,” until Galileo resolved it and described it in his Nuncius Sidereus as as cluster of “more than forty small stars.” In China it has long had associations with ghosts and the underworld.
M44, by Dogwood Ridge Observatory
This is yet another example of how stars of lesser visibility can be used for navigation thanks to a sophisticated system of correlations and counterchecks. The nautical practice involves assiduously checking the celestial angles and the culmination points of certain stars, and it is extremely similar to the astrological use of paranatellonta (“the ones rising in combination,“ from παρανατέλλω). It required great experience and knowledge, and in turn it endowed the pilots with a remarkable degree of accuracy. This is why Ibn Mājid decries the vagueness of those pilots who said, “oh, it is just a trifle of an eighth of a finger’s difference!“ When a difference of an eighth of a (nautical) “finger” means a difference of twenty miles in your landfall, it can mean a difference between life and a shipwreck! [JA]