The Arabs knew the earth was spherical early on and the librarian of Alexandria had calculated the radius with the famous "well" experiment at a solstice (or was it the equinox?). That value was very close; much better than the one Columbus used. Keep in mind, the Europeans were well behind the times after the fall of Rome and for many hundred years after that. In 1300 they still believed in mountain spirits causing miners lung disease and in the early 1800 worried about swamp gas.But back to the topic, these antique methods are still useful as I found out in a Chi-Mac race in '91. And the knowledge of those methods aids in understanding some modern equipment.Useful for off shore and coastal boaters.RonWild CheriC&C 30STL
--- On Mon, 1/28/13, Jim Brown <jimbrownfl...@telus.net> wrote: From: Jim Brown <jimbrownfl...@telus.net> Subject: Re: Stus-List Sextant To: cnc-list@cnc-list.com Date: Monday, January 28, 2013, 3:55 PM Just a sideline to the notion that Europeans in the 15th century may have believed that the world was flat , in Capt. Joshua Slocum’s “Sailing Alone Around the World” he mentions his meeting with President Kruger – the President of the Transvaal in South Africa. Upon being presented to the President as one who was on a voyage around the world, Slocum discovered that President Kruger firmly believed that the world was flat and made a point of “correcting” the matter. This was in 1897! Jim Brown“Flash Over” 1981 C&C 34Vancouver, BC From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Jack Brennan Sent: January-28-13 10:02 AM To: cnc-list@cnc-list.com Subject: Re: Stus-List Sextant The idea that Europeans thought the Earth was flat until the 15th century is one of the great myths of modern history, apparently invented and perpetuated by some 19th century writers. It’s a fascinating story about how it actually made it into history books. I have a book somewhere that tells the story. Most historians believe that educated people, from the time of the Greeks, always knew the Earth was spherical. Columbus’ problem was that he didn’t believe the ancient Greeks who used the horizon to make a pretty good guess about the size of the Earth. He thought it was much smaller. An interesting belief that was prevalent, however, was that Antarctica was a large, temperate continent with millions of people living there. Some ambitious early explorers actually returned and told tall tales about visiting there. Jack Brennan Shanachie, 1974 Bristol 30Former C&C 25 Fort Lauderdale, Fl. From: Ronald B. Frerker Sent: Monday, January 28, 2013 11:34 AMTo: cnc-list@cnc-list.com Subject: Re: Stus-List Sextant Greeks and Arabs were aware of a round earth back in 400BC. After the Greek epicycle fiasco, they probably figured out about the earth rotating about the sun.Given the Arabs early knowledge of navigation, they might well have known this also but Europe didn't always have knowledge of their early science; even to today. Their astrolabe seemed to have a lot of info. I haven't figured out anything more than its basic angle measurement.Staffs and backstaffs predate the sextant for measuring and of course, the knotted string/wood dowel also. Quadrant in Columbus' time. Europe on board with heliocentric theory about 1500AD; completely abandoned flat earth finally around 1500AD, probably some much earlier.Polynesians were seafarers, would be interesting to know their theory of the celestial relationship.RonWild CheriC&C 30STL From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of dwight veinot Sent: Monday, January 28, 2013 10:01 AM To: cnc-list@cnc-list.com Subject: Re: Stus-List Sextant Was the sextant invented before we knew the difference? Dwight VeinotC&C 35 MKII, AliannaHead of St. Margaret's Bay, NSFrom: CnC-List [wlmailhtml:/mc/compose?to=cnc-list-boun...@cnc-list.com] On Behalf Of Frederick G Street Sent: January 28, 2013 10:45 AM To: wlmailhtml:/mc/compose?to=cnc-list@cnc-list.com Subject: Re: Stus-List Sextant Yes, that's common knowledge; but the process of doing celestial navigation actually presumes that the earth (or your location on it) is fixed, and the sun is doing the moving. Here's one of the more concise books on the topic: http://www.amazon.com/Celestial-Navigation-Yachtsmen-Mary-Blewitt/dp/0070059284 Fred Street -- Minneapolis S/V Oceanis (1979 C&C Landfall 38) -- on the hard in Bayfield , WI :^( On Jan 28, 2013, at 6:01 AM, dwight veinot <wlmailhtml:/mc/compose?to=dwightvei...@hfx.eastlink.ca> wrote: Is it not common knowledge that the sun essentially remains fixed for all intents and purposes and the earth does the moving? _______________________________________________ This List is provided by the C&C Photo Album http://www.cncphotoalbum.com CnC-List@cnc-list.com -----Inline Attachment Follows----- _______________________________________________ This List is provided by the C&C Photo Album http://www.cncphotoalbum.com CnC-List@cnc-list.com
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