Nicholas Carey
08-04-2003, 03:01 PM
A Seattleite, Leif Karlsen, has writting an interesting book on navigation with Viking 'sunstones'. I ran across it at the bookstore the other day—I'm not used to picking up a book, noticing the author's name and going...."Wait a second! I know this guy!".
I haven't read it yet, but Leif does know his stuff.
Secrets of the Viking Navigators: How the Vikings Used their Amazing Sunstone and Other Techniques to Cross the Open Ocean (http://www.oneearthpress.com/cgi-bin/books.pl)
Essentially, the Vikings used the polarised nature of sunlight and the refractive properties of feldspar crystals to give them what amounted to a sun sight. It works, even in overcast weather, as light doesn't stop being polarised.
From my quick browsing of the book last night, it looks good. Leif says, if I read right, that a sunstone fix locates the sun about as well as a sextant (maybe better since it works when it's overcast).
Available from The Armchair Sailor (http://www.armchairsailorseattle.com/index.htm), as well as The Usual Places (http://www.amazon.com/exec/obidos/ASIN/0972151508/qid%3D1060022033/sr%3D11-1/ref%3Dsr_11_1/102-3890621-4398514).
I haven't read it yet, but Leif does know his stuff.
Secrets of the Viking Navigators: How the Vikings Used their Amazing Sunstone and Other Techniques to Cross the Open Ocean (http://www.oneearthpress.com/cgi-bin/books.pl)
Essentially, the Vikings used the polarised nature of sunlight and the refractive properties of feldspar crystals to give them what amounted to a sun sight. It works, even in overcast weather, as light doesn't stop being polarised.
From my quick browsing of the book last night, it looks good. Leif says, if I read right, that a sunstone fix locates the sun about as well as a sextant (maybe better since it works when it's overcast).
Available from The Armchair Sailor (http://www.armchairsailorseattle.com/index.htm), as well as The Usual Places (http://www.amazon.com/exec/obidos/ASIN/0972151508/qid%3D1060022033/sr%3D11-1/ref%3Dsr_11_1/102-3890621-4398514).