Apparently the myth that medieval people believed that the earth was flat was a 19th century creation that was perpetuated by a novel about Christopher Columbus by Irving Washington (I think that was his name).


If it's the same guy who wrote The Legend of Sleepy Hollow, his name is Washington Irving. Close

Tom

Yeah, that'll be him. I find it interesting that these sorts of myths are so easily created and believed. As I said, there was a time when I believed that they thought the world was flat in the Middle Ages.

Speaking of Columbus, apparently one of the reasons he sailed off on his voyages of discovery was because he had read the works of Cardinal Pierre d'Ailly, a French astrologer who had predicted that the world would end in 1789, actually the start of the French Revolution. (For some reason Columbus reduced this figure to 155 years when he wrote to his patrons Ferdinand and Isabella of Spain.) Columbus wanted to make sure that the world was Christianised by then. He also accepted the calculations of d'Ailly that put the circumference of the earth at substantially smaller than it already was, making him believe that his journey would be easier than it was. Laura Smoller opens with this story in her fascinating book on d'Ailly. Apparently there are extant copies of the works of d'Ailly heavily annotated by Columbus.

Hi Tom & All -

While I'm still interested in developing this notion of mundane signature and tarcing it's references since Ptolemy, this stuff on Cardinal Pierre d'Ailly and Columbus is also fascinating. d'Ailly's world dominated by the crown and the church certainly did end with the revolution but it would be interesting to see why he thought it would be so and to have a look at the charts he used to consider it. In 1492, the Hundred Years War between the French and English was just winding out. Heretics and witches were still being burned and the Turk was knocking on the door at Vienna. Quite an interesting time in itself.

A little diversion into d'Ailly and astrologers of this period, perhaps including some of the Islamic lights of the Art would be welcome and it might turn up insight into this issue as well as some other mundane techniques or methods of interest. It should be kept in mind that d'Ailly's ephemerides were before the reform and corrections of Kepler, so some of his claculations may differ from positions obtained from software.

A chart for the storming of the Bastille shouldn't be too hard to come by.