on.

* * * * *

CHAP. VIII.

Of Discords between pieces of Iron upon the same pole
of a loadstone, and how they can agree and
_stand joined together_.

Suppose two iron wires or a pair of needles stuck on the pole of a
terrella; though they ought to stand perpendicularly, they mutually repel
one another at the upper * end, and produce the appearance of a fork; and
if one end be forcibly impelled toward the other, the other declines and
bends away from association with it, as in the following figure.
[Illustration] {133} A and B, iron spikes, adhaere obliquely[207] upon the
pole on account of their nearness to one another; either alone would
otherwise stand erect and perpendicular. For the extremities A B, being of
the same verticity, mutually abhor and fly one another. For if C be the
northern pole of the terrella, A and B are also northern ends; but the ends
which are joined to and held at the pole C are both * southern. But if
those spikes be a little longer (as, for example, of two digits length) and
be joined by force, they adhaere together and unite in a friendly style,
and are not separated without force. For they are magnetically welded, and
there are now no longer two distinct ends, but one end and one body; no
less than a wire which is doubled and set up perpendicularly. But here is
seen also another subtile point, that if those spikes were shorter, not as
much as the * breadth of one digit, or even the length of a barleycorn,
they are in no way willing to harmonize or to stand straight up at the same
time, because naturally in shorter wires the verticity is stronger in the
ends which are distant from the terrella and the magnetick discord more
vehement than in long ones. Wherefore they in no way admit of an intimate
association and connection.

[Illustration]

Likewise if those lighter pieces of iron or iron wires be suspended,
hanging, as A and B, from a very fine silk thread, not twisted * but
braided, distant from the stone the length of a single barleycorn, then the
opposing ends, A and B, being situated within the orbe of virtue above the
pole, keep a little away from one another for the same reason; except when
they are very near the pole of the stone C, the stone then attracting them
more strongly toward one end.

* * * * *

{134} CHAP. IX.

Figures illustrating direction and showing varieties
_of rotations_.

[Illustration]