Communication with Nostradamus was done trough a mirror sitting on Nostradamus desk.
He was drawing Horoscope charts using an instrument like a compass. He was working with the arcs of different planetary energies. He is been working on the arc of energy emanating from Mars and contemplating how it is affecting Europe at this time.
( At the present moment can we produce similar reports or research without dismissing them as science fiction? Have we evolved enough to open the possibilities that his research is valid and recreate it?)
He has studied Ptolemy and Kricinimos astronomy in the Greek and Roman period.
Mars rules the war. Mars is emanating a lot of energy in that area of the world ( Europe) at his time.
Kritodemos was one of the pioneers and founders of astrology. He was one the first Greeks to directly use Babylonian astrology or drawn upon Babylonian sources.
After fall of the Roman Empire the Arabs developed divinatory astrology into a science.
Astrology was taught in the universities of Europe from the 12 – 16 th centuries.
Nostradamus made a trip to Malta to met with Arab scientist to learn about astrology. A lot of formulas were written by the ancient astrologers to measure the arc of energy emanated by Mars.
Many astrological documents were destroyed when the Alexandrian library was burned. But some of the information was carried on by the people of the Arab world.
Malta was under Muslim rule after Arabs conquered it in 870 until 1090. In 1530 ( the time of Nostradamus) tho Holy Roman Emperor granted Malta to the Knights of St John of Jerusalem.
from Conversation with Nostradamus volume 2 by Dolores Cannon