h is more prevalent on the greater
continent and not in the aquaeous or fluid or unstable part; [219]it
follows that in certain parts there would be a magnetick inclination from
the true pole east or west away from any meridian (whether passing through
seas or islands) toward a great land or continent rising higher, that is,
obviously toward a stronger and more elevated magnetick part of the
terrestrial globe. For since the diameter of the earth is more than 1,700
German miles, those large lands can rise from the centre of the earth more
than four miles above the depth of the ocean bottom, and yet the earth will
retain the form of a globe although somewhat uneven at the top. Wherefore a
magnetical body is turned aside, so far as the true verticity, when
disturbed, admits, and departs from its right (the whole earth moving it)
toward a vast prominent mass of land as though toward what is stronger. But
the variation does really take place, not so much because of the more
prominent and imperfect terrestrial parts and continent lands as because of
the inaequality of the magnetick globe, and because of the real earth,
which stands out more under the continent lands than under the depths of
the seas. We must see, therefore, how the _apodixis_ of this theory can be
sustained by more definite observations. Since throughout all the course
from the coast of Guinea to Cape Verde, the Canary Isles, and the border of
the kingdom of Morocco, and {154} thence along the coasts of Spain, France,
England, Belgium, Germany, Denmark, and Norway, there lie on the right hand
and toward the east a continent and extensive connected regions, and on the
left extensive seas and a vast ocean lie open far and wide, it is consonant
with the theory (as has been carefully observed by many) that magnetical
bodies should turn slightly to the East from the true pole toward the
stronger and more remarkable elevations of the earth. But it is far
otherwise on the eastern shores of northern America; for from Florida by
Virginia and Norumbega to Cape Race and away to the north the versorium is
turned toward the west. But in the middle spaces, so to speak, as in the
more westerly Azores, it looks toward the true pole. That any magnetick
body turns itself similarly to the same regions of the earth is not,
however, because of that meridian or because of the concordancy of the
meridian with any magnetick pole, as the crowd of philosophizers reckon,
for it is not so