[a short post, for a change. With a maths problem. Additional illustration added 17th April 2017; further illustration added 18/04/20177]
To say that the Voynich map represents ‘four continents’ is inaccurate: what we see is a custom by which the maker’s world was envisaged as square and for that reason envisaged fourfold. The custom was not European but was – as we’ve seen – conventional among the Chinese.
As now bound, the map has its north almost ‘up’ (upper right) though East still lies to the viewer’s upper-left in another custom not the Latins’ but attested in the east, particularly when making maps of the heavens.
I add another illustration of that custom (click to enlarge):
This blog is hardly the place for a disquisition on that close historical connection we know to exist between the custom of making maps and of representing cosmology, so I’ll content myself with reminding readers that the imposition of a celestial grid on the surface of sea or land is the essence of traditional navigation among nomads and eastern mariners, across the wastes of sand or of sea. (Subjective experience leads often to describing the process inversely, as the tracing of a ‘sky-road’ which then, moving overhead, carries one towards the unseen destination).
Precisely the same principle informs our own sidereal surveying, still essential in the curriculum of any would be engineer-surveyor (B.Sc. Eng) until the middle of last century. With the help of various instruments, sets of tables, pen-and-paper calculations and a copy of the Nautical Almanac, he set about solving problems such as that below, which I add just to break the monotony. Answer is published as a ‘comment’ below this post. The problem comes from a text published in 1955:
For observations in southern England, draw a rough sketch of the celestial sphere, marking on it the zenith Z. Show the celestial poles PP and the equator, and mark the approximate position S of a star of declination roughly 30º N. about four hours before its upper transit. Sketch in the declination circle and vertical circle of the star, and show how the solution of the spherical triangle PZS can be used to determine the azimuth of the point of observation.
From a station in latitude 50° 40′ 40″ N. the bearing of a star from a referring object R was 86° 42′ 00″. The mean altitude measured at the same time, corrected for refraction, was 52° 16′ 00″. The declination was 29° 42′ 08″. Determine the azimuth of the object R. The star was in the west at the time.
Its not only about location, but about relative positioning.
And so to resume..
The Voynich map’s having North to the top and East to the left would not be surprising, nor need excuses created for it, if one accepts that the map may reflect not only eastern customs in representing the form of the square world, but more generally an eastern-influenced cosmography.
Its containing a ‘navel of the world’ need not disturb us, either. It is worth remembering that even among Latins of the far west, some knowledge of ancient Ujjain as a semi-mythical ‘Arin’ had penetrated by the early twelfth century.
Peter Alphonsi knows it, a mid-life convert from Judaism who brought much of his astronomical learning to the Latins after his conversion in 1106. So then Michael Scot, who knew of ‘the tables of Arin’ but made use of the Toledan. Roger Bacon also and others after him accepted that the semi-mythical Arin, not Jerusalem, stood at the physical centre of the world.. and so it continues.. until in 1498, Columbus says in writing to the king and queen during his third voyage that, “Ptolemy and the other philosophers who have written on the globe thought that it was spherical, believing that this  hemisphere was round, as well as that in which they themselves dwelt, the centre of which was the island of Arin, which is under the equinoctial line, between the Arabian Gulf and the Gulf of Persia.” Interestingly, the centre of the Voynich map shows a great lake in that island;
ancient Ujaiin had indeed stood by a a lake which can be seen on early maps such as the Tabula Peutingeriana, but which apparently breached at the time of the great disaster which destroyed Muziris. The ‘cupola(s)’ of Arin were also proverbial.
In my opinion, if it is not Arin, it is meant for Raidan – but explaining that isn’t something I want to do through voynichimagery, sorry.
 To the day he died, Columbus insisted that he had not discovered a ‘new world’ but, as he intended, reached India.
 Hobson-Jobson, ‘Oojyne’ proved delightfully well informed on Arin/Ujjain, and I cite it here chiefly for the pleasure of having that opportunity.
The conclusion of this series (Pt 2-ii) isn’t so short. 🙂