On the variation under the æquinoctial line,
_and near it_.
In the North the magnetick needle varies because of the Boreal eminences of
the continent; in the South because of the Austral; at the æquator, if the
regions on both sides were equal, there would be no variation. But because
this rarely happens some variation is often observed under the æquator; and
even at some distance from the æquator of three or 4 degrees toward the
North, there may be a variation arising from the south, if those very wide
and influential southern continents be somewhat near on one side.
* * * * *