eaker and is moved more feebly. As to
Fracastorio's[162] statement that he saw a piece of loadstone draw a
loadstone by one of its faces, but not iron; by another face iron, but not
loadstone; by another both; which he says is an indication that in one part
there is more of the loadstone, in another more of the iron, in another
both equally, whence arises that diversity of attraction; it is most
incorrect and badly observed on the part of Fracastorio, who did not know
how to apply skilfully loadstone to loadstone. A loadstone draws iron and
also a loadstone, if both are suitably arranged and free and unrestrained.
That is removed more quickly from its position and place which is lighter;
for the heavier bodies are in weight, the more they resist; but the lighter
both moves itself to meet the heavier and is allured by the other.

* * * * *

CHAP. V.

How the Power dwells in the
_Loadstone_.

That a loadstone attracts loadstone, iron and other magnetical bodies, has
been shown above in the previous book, and also with what strength the
magnetick coition is ordered; but now we must inquire how that vigour is
disposed in a magnetick substance. And indeed an analogy must be inferred
from a large loadstone. Any magnetick substance joins itself with a
loadstone strongly, if the loadstone itself is strong; but more weakly,
when it is somewhat imperfect or has been weakened by some flaw. A
loadstone does not draw iron equally well with every part; or a magnetick
substance does not approach every part of a loadstone alike; because a
loadstone has its points, that is its true poles, in which an exceptional
virtue excels. Parts nearer the pole are {72} stronger, those far away more
weak, and yet in all the power is in a certain way equal. The poles of a
terrella are A, B; the aequinoctial is C, D. At A and B the alluring force
seems greatest.

[Illustration]

At C and D there is no force alluring magnetick ends to the body, for the
forces tend toward both poles. But direction is powerful on the aequator.
At C, D, the distances are equal from both poles; therefore iron which is
at C, D, when it is allured in contrary ways, does not adhaere with
constancy; but it remains and is joined to the stone, if only it incline to
the one or other side. At E there is a greater power of alluring than at F,
because E is nearer the pole. This is not so because there is really
greater virtue residing at the p