This is a MapHist list message. News: If you don't get messages anymore, go to http://www.maphist.nl for news about the new MapHist Forum o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o +
The numbers seem to obey the relation 17.5 / cos D, with D representing the compass direction (measured from the north). However, the last two numbers (88 and 0) should then read 90 (rounded from 89.7) and infinity. Rob van Gent -----Original Message----- From: maphist-boun...@geo.uu.nl [mailto:maphist-boun...@geo.uu.nl] On Behalf Of Vladimiro Valerio Sent: dinsdag 27 december 2011 11:21 To: Discussion group for map history Subject: Re: [MapHist] Odd Numbers on an Old Wind Rose This is a MapHist list message. News: If you don't get messages anymore, go to http://www.maphist.nl for news about the new MapHist Forum o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + Me too, I will be interested in receiving an image. You may sent at my address also a big one (up to 10 MB). vladimiro vladi...@iuav.it Il giorno 27/dic/2011, alle ore 10.41, Joaquim Alves Gaspar ha scritto: > This is a MapHist list message. > News: If you don't get messages anymore, go to http://www.maphist.nl > for news about the new MapHist Forum o + o + o + o + o + o + o + o + o > + o + o + o + o + o + o + o + o + o + o + > > > Hi Bill & all, > > We have 32 points in a wind rose but you only refer to 9 in each direction. > It would also be nice to have an image even a small one (does the system > allow it to be attached?). > > Joaquim > > De: maphist-boun...@geo.uu.nl [mailto:maphist-boun...@geo.uu.nl] Em > nome de Bill Thoen > Enviada: terça-feira, 27 de Dezembro de 2011 02:32 > Para: maphist@geo.uu.nl > Assunto: [MapHist] Odd Numbers on an Old Wind Rose > > I recently was asked a question about a compass or wind rose that had > some odd numbers marking the 32 points. Instead of degrees or points > it's marked 17 1/2 over the fleur de lis at north and then in both > directions, every 11.25 degrees the markings go > 18 > 19 > 21 > 25 > 31 1/2 > 46 > 88 > 0 at due west and due east. > The actual angles are 11.25 degrees per division, but if you plot these > numbers against the actual angles you get a very smooth curve that looks > exponential or maybe logarithmic. This graphic was seen in the Ch. Columbus > museum on Porto Santo, a small island of Madeira, Portugal. > > > The question is, what do these numbers mean? I've got a couple of > images, but they're too big to show you here. I thought I'd just ask > if anyone knows anything about this sort of numbering before I go to > further lengths. For all I know this could be an easy one. I just > can't figure out if this is some sort trigonometry calculator or what > it was supposed to do for the mariner of Columbus' time. (I don't have > a date for it either; I'm assuming it's 15th century.) > > So is this a common numbering scheme or do you need to see the pictures? > > Regards, > > Bill Thoen > GISnet > http://gisnet.com > 303-786-9961 > _______________________________________________ > MapHist: E-mail discussion group on the history of cartography hosted > by the Faculty of Geosciences, University of Utrecht. > The statements and opinions expressed in this message are those of the > author and do not necessarily reflect those of the University of > Utrecht. The University of Utrecht does not take any responsibility > for the views of the author. > List Information: http://www.maphist.nl > > Maphist mailing list > Maphist@geo.uu.nl > http://mailman.geo.uu.nl/mailman/listinfo/maphist _______________________________________________ MapHist: E-mail discussion group on the history of cartography hosted by the Faculty of Geosciences, University of Utrecht. The statements and opinions expressed in this message are those of the author and do not necessarily reflect those of the University of Utrecht. The University of Utrecht does not take any responsibility for the views of the author. List Information: http://www.maphist.nl Maphist mailing list Maphist@geo.uu.nl http://mailman.geo.uu.nl/mailman/listinfo/maphist _______________________________________________ MapHist: E-mail discussion group on the history of cartography hosted by the Faculty of Geosciences, University of Utrecht. The statements and opinions expressed in this message are those of the author and do not necessarily reflect those of the University of Utrecht. The University of Utrecht does not take any responsibility for the views of the author. List Information: http://www.maphist.nl Maphist mailing list Maphist@geo.uu.nl http://mailman.geo.uu.nl/mailman/listinfo/maphist
