CHAP. XIIII.
On the variation under the æquinoctial line,
and near it.
n 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.