Portolan Map Possibilities

[Linda]

The 12th century charts of Al-Idrisi are not to be missed. Even if they have no direct bearing on the VMS, they did set a new standard for cartography in the west and they are marvelous.

He was a Moroccan who spent many years in Sicily creating the charts for Roger II.

You are not allowed to view links. Register or Login to view.

Indirectly related to Voynichese... they are useful in assessing the language structure of Arabic labels. The initial labels were Arabic, Al-Idrisi's native script, but some of the charts have been transliterated into Latin characters. Once again, one notices that the natural language labels are far more positionally varied than VMS labels.

Yes, need to find charts of any kind to get an idea of the structure. 

Although i can envision the determination of the windroses, i dont know what kind of coordinate system was used to plot the points. 

I know they went by pilot rutters but these are local descriptions and probably varied in their makeup from place to place. I read that compass bearings were not necessarily used, that it was triangulation that determined the location of a point from the angles of two known locations. In some cases it would be trilateration, with the actual distances being known.

If we know where Vesuvius is and we know some other line of sight location, like that point that juts out from Naples, we can figure out a third and so forth. But correlation to the imagery is one thing, the text correlation is another thing completely, and unfortunately most rutters dont exist either.



You are not allowed to view links. Register or Login to view.

This states sailors would travel north or south until the altura or height of the pole star matched that of the chart for their destination, then sail east or west on that altura until they hit land.

Could this be the meaning of the stars beside the zodiac nymphs? Interesting how altura can also mean period, as in time of the past. Is that why the tails on some of the stars? 

You are not allowed to view links. Register or Login to view.

This describes an unpublished portolan. It is interesting, there are some correlations, like mentioning the guadalquivir river in passing, but going on to Gibraltar. It mentions glass manufacture at Murano, evidently this is not mentioned in any other portolan. It compares to others, and it seems that parts of each describe what I have seen outlined in quire 13. The Compasso da navegare seems to match best, although i need to read more.