of the earth, just as toward a pole of the terrella:
By its being placed down also, and cooling toward the earth's pole after
the pristine verticity has {212} been annulled by fire, it acquires new
verticity, conformable to its position earthward. Iron rods also, when
placed some considerable time toward the poles, acquire verticity merely by
regarding the earth; just as the same rods, if placed toward the pole of a
loadstone, even without touching it, receive polar virtue. There is no
magnetick body that in any way runs to the terrella which does not also
wait upon the earth. As a loadstone is stronger at one end on one side or
other[240] of its aequator: so is the same property displayed by a small
terrella upon the surface of a larger terrella. According to the variety
and artistick skill in the rubbing of the magnetick iron upon the terrella,
so do the magnetick things perform their function more efficiently or more
feebly. In motions toward the earth's body, as toward the terrella a
variation is displayed due to the unlikeness, inequality, and imperfection
of its eminences: So every variation of the versorium or mariners' compass,
everywhere by land or by sea, which thing has so sorely disturbed men's
minds, is discerned and recognized as due to the same causes. The magnetick
dip (which is the wonderful turning of magnetick things to the body of the
terrella) in systematick course, is seen in clearer light to be the same
thing upon the earth. And that single experiment, by a wonderful
indication, as with a finger, proclaims the grand magnetick nature of the
earth to be innate and diffused through all her inward parts. A magnetick
vigour exists then in the earth just as in the terrella, which is a part of
the earth, homogenic in nature with it, but rounded by Art, so as to
correspond with the earth's globous shape and in order that in the chief
experiments it might accord with the globe of the earth.

* * * * *

CHAP. II.

The Magnetick axis of the Earth
_persists invariable_.

As in the very first beginnings of the moving world, the earth's magnetick
axis passed through the midst of the earth: so now it tends through the
centre to the same points of the superficies; the circle and plane of the
aequinoctial line also persisting. For not without the vastest overthrow of
the terrene mass can these natural boundaries be changed, as it is easy to
gather from magnetick demonstrations.