Source: http://www.ancient-wisdom.com/Ghizawhen.htm

The twelve wind system:

The Piri-ries map was composed using an ancient system of cartography that involved the division of a circle from an original multiple of 360 degrees. This fact relates the system to Babylonian science in which the Babylonians had a numbering system based on sixty and on decimals. The Babylonians also had the zodiac, with twelve signs of 30 degrees separation between each. (The twelve-wind system produces a 6×6 grid from divisions of 24 arcs of 15 degrees each – The eight-wind system produces a 4×4 grid from 8 arcs of 22.5 degrees each – The Piri-reis map has 30 arcs of 12 degrees each).

(Extracts from ‘Maps of the Ancient Sea Kings’, By C. Hapgood) – Various writers refer to the use of the twelve-wind system among the ancients. The Greek geographer Timosthenes, an immediate predecessor to Eratosthenes employed it. The later was said to have abandoned it in favour of the eight-wind system, because it was too difficult for mariners.

It is interesting to note that the 8×8 grid (made of the first 64 numbers), in its ‘Magic square’ form, represents Mercury (Hermes, Thoth), which is also the planet ascribed the Pyramids by J. Michell. Each planet associated to a different ‘Ancient wonder of the world’. He quotes the cabbalist Levi who said the following ‘the whole secret of prehistoric science is expressed in the following equation’ referring to the idea that all life is created by the fusion (alchemy) of Mercury (1080) and Sulphur (666) = 1746. This number, used as a circumference, will create a pyramid with exactly the same dimensions of the Great pyramid.

In conclusion, the 8×8 grid that is used in the design of Giza is the same as that used in the construction of ancient navigational charts.

The same grid produces the 12 x 30 degree arcs of the Sumerians, and the oldest maps using this system appear to have centred on Cairo and been made between 13,000 and 4,000 BC. During this time period, Earth was subjected to a 120 metre sea level rise, consisting of three flood phases as explored below. The Sumerians disappeared (along with other cultures), at the end of this time frame.