KIRIBATI ASTRONOMY AND NAVIGATION
There is no word for "astronomer" in the Gilbertese language. If you wished to find an expert on the stars you asked for a tiaborau or navigator, astronomy being looked on as only an adjunct to the larger science of navigation. |
We know that stone circles, in Britain and elsewhere, were laid out some 4,000 years ago as instruments by which men could observe the heavens to predict eclipses and movements of sun, moon and stars. These circles were so sited that alignments between heavenly bodies and certain landmarks met within he perimeters of stone. There they formed geometrical patterns illustrating mathematical concepts so advanced as to be incompatible with stories of a primitive prehistoric society.
From China, India, Egypt, the Euphrates valley, parts of Africa and Central America comes other evidence that many thousands of years ago there existed a civilisation of an intellectual and moral quality inconceivable to us today ... The cultural void which today renders so much effort futile is no inheritance from the past. The great civilisation which declined and was lost some 5,500 years ago was based on the memory of a great vision through which all men had access to a state of enlightenment ... They knew the places where the rise and fall of heavenly bodies could be interpreted in geometric forms and from these into mathematics and poetry.
They lived in absolute certainty, following in all they did the rhythm of the stars until, as memory began to fade, a vast system of oral traditions began to replace what hitherto all men had known. As guardian of these traditions, a body of priests came into being. Under their influence the universal civilisation began to break up, rival groups of interpreters leading their followers in different directions ...
There is no word for "astronomer" in the Gilbertese language. If you wished to find an expert on the stars you asked for a tiaborau or navigator, astronomy being looked on as only an adjunct to the larger science of navigation. This made it difficult to get reliable information on Gilbertese astronomical observances because, with the arrival of European ships and easy travelling, followed by Government regulations controlling inter-island voyages, navigation had become a dying art.
In the Gilbert Islands, those who could speak with authority about the stars, and those who had the knowledge were often unwilling to pass it on, for of all secrets those connected with navigation were the most jealously prized and guarded. Nevertheless, there were still greybeards in the group who had made voyages of a thousand miles in canoes sewn together with strings; and until some thirty years earlier, inter-island trips of two hundred and fifty miles and more were regularly made in these craft for the purpose of exchanging dances!
What could be finally learned - especially certain facts connected with movements of the sun - made it clear that the Gilbertese ancestors came into Oceania equipped with a system of navigation based on the observation of heavenly bodies, and that they had learned it from people possessed of a mathematical system. Most of this information came from Biria, an old man of Butaritari, who sixty years before had been instructed in navigation. His training lasted seven years, during which time he learned to drink sea water - a little every day - until his body became so accustomed to it that he could live for weeks on end without any fresh water at all.
He also learned about he stars, but not under the sky; his lessons began in the village maneaba where he was made to sit at the base of the central pillar facing the eastern slope of the roof. Just as the roof was divided by lines of rafters, so the heavens were plotted out for him in lines of principal stars. Every constellation was allotted to imaginary place in the thatch, according to what we would call its angular distance east or west of Rigel and its declination north or south of that star.
Aspects of the Heavens
The Gilbertese navigator regards the night-sky as a vast roof. He never calls it karawa, the usual term for the heavens, but applies to it the special name uma ni borau, which signified literally 'roof of voyaging'. His whole terminology of the skies follows consistently upon this fundamental idea. He calls the eastern horizon te tatanga ni mainiku (the roof-plate of east) and the western, in a similar manner, te tatanga ni maeao (the roof-plate of west). The meridian is te taubuki, the ridge-pole.
The roof is supported by imaginary rafters (oka), three on the eastern slope and three to correspond on the west. The apex of the middle pair is held to be at the point where the star Rigel (beta Orionis) crosses the meridian. These middle rafters represent the Gilbertese celestial equator, which, being fixed by the declination of Rigel, is seen to be placed about 8 degrees south of our own. The apex of the northern pair of rafters is said to be where the Pleiades cross the meridian, which is about 24 degrees north of the true celestial equator and 32 degrees north of the Gilbertese; while the star Antares (alpha Scorpionis) marks the meeting-point of the southern pair at 26 degrees true south declination, or 18 degrees south of the Gilbertese equator.
Lying across three rafters, like the steps of a ladder up the sky, the astronomer imagines a series of three equally spaced cross-beams or purlins on each slope of the roof. The following diagram, then, illustrates his conception of the eastern sky from horizon to meridian.
His idea of the western sky is exactly the same, but the numbers the purlins downwards from meridian to horizon. The navigator sits in imagination beneath this immense framework, upon which the stars themselves form the ever-shifting thatch. It is by reference to the purlins that he expresses the altitude of a heavenly body above the horizon, while the rafters afford him a rough measure of declination. For a greater accuracy in indicating altitude, each of the intervals between the purlins is divided into two compartments, as shown by the dotted lines in the diagram. The eastern half (i.e. the lower half on the eastern side and the upper half on the western side of the roof) is called te marena ni bong (the interval of days or seasons) and the western half is te nikanewe (the sacred enclosure). The marena ni bong is said to 'belong to' the purlin bounding it to eastward, and the nikanewe to that which defines its western limit. In the diagram of the eastern sky above, the inferior half of each interval is therefore a marena ni bong, and 'belongs to' the purlin beneath it; while the superior half is a nikanewe, and belongs to the purlin above it. From this it is seen that the various stages in the passage of a star from horizon to meridian are indicated as follows by a Gilbertese navigator:
One of the methods of memorising the guiding stars on any specific course was to weave the tale about them, wherein they figured as persons or objects seen during the voyage of some fictitious character. Very often, the better known folk stories of the race were adapted to this purpose. Some popular hero of myth is said to have set out on a journey to a particular place; first he came across an old woman sitting at the door of her house (Pleiades), on whom he played some familiar trick, which caused her to run away westward (i.e. decline towards her setting). Next, he met a man coming from a canoe in the east (this is to say, he then steered by the star Aldebaran in the constellation of Taurus, which is V-shaped, like the section of a canoe). With him he held a conversation until the old woman, who had run away from him, fell into the sea (the Pleiades set); she made such a dreadful noise that the hero of the tale ran away to eastward and took refuge with two old lepers (Gemini).
And so the story went on until the tale unfolded the whole series of stars by which a canoe is guided to some particular land.
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