ole, but since all the parts are united in
the whole, they direct their forces towards the pole. From the forces
flowing from the plane of the aequinoctial towards the pole, the power
increases. A fixed verticity exists at the pole, so long as the loadstone
remains whole; if it is divided or broken, the verticity obtains other *
positions in the parts into which it is divided. For the verticity always
changes in consequence of any change in the mass, and for this cause, if
the terrella be divided from A to B, so that there are two stones, the
poles will not be A, B, in the divided parts, but F, G, and H, I.

[Illustration] {73}

Although these stones now are in agreement with one another, so that F
would not seek H, yet if A was previously the boreal pole[163], F is now
boreal, and H also boreal; for the verticity is not changed (as Baptista
Porta incorrectly affirms in the fourth chapter of his seventh book);
since, though F and H do not agree, so that the one would incline to the
other, yet both turn to the same point of the horizon. If the hemisphere H
I be divided into two quadrants, the one pole takes up its position in H,
the other in I. The whole mass of the stone, as I have said, retains the
site of its vertex constant; and any part of the stone, before it was cut
out from the block[164], might have been the pole or vertex. But concerning
this more under _Direction_. It is important now to comprehend and to keep
firmly in mind that the vertices are strong on account of the force of the
whole, so that (the command being, as it were, divided by the aequinoctial)
all the forces on one side tend towards the north; but those of an opposite
way towards the south, so long as the parts are united, as in the following
demonstration.

[Illustration]

For so, by an infinite number of curves from every point of the equator
dividing the sphere into two equal parts, and from every point of the
surface from the aequator towards the North, and from the aequator towards
the Southern pole, the whole force tends asunder toward the poles. So the
verticity is from the aequinoctial {74} circle towards the pole in each
direction. Such is the power reposed in the undivided stone. From A vigour
is sent to B, from A, B, to C, from A, B, C, to D, and from them likewise
to E. In like manner from G to H, and so forth, as long as the whole is
united. But if a piece A B be cut out (although it is near the aequator),
yet it will be as stron