assing the Strait of Magellan the
deviation on the shore of Peru is toward the south-east, i.e., from the south toward the east. And a similar
deflection would be continued along the whole coast of Peru as far as the æquator. In a higher latitude up to 45 deg. the
variation is greater than near the æquator; and the deflection toward the south-east is in nearly the same proportion as
was the deviation from the south toward the west on the eastern shore of South America. From the æquator toward the North
there is little or no variation until one comes to New Galicia; and thence along the whole shore as far as Quivira the
inclination is from the north toward the east.
http://ebooks.adelaide.edu.au/g/gilbert/william/on-the-magnet/book4.17.html
Last updated Wednesday, September 12, 2012 at 16:19