CHAP. XVIII.

An armed Loadstone does not endow an

excited piece of Iron with greater vigour

_than an unarmed_.

Suppose there are two pieces of iron, one of * which has been excited by an

armed loadstone, the other by one unarmed; and let there be applied to one

of them another piece of iron of a weight just proportional to its

strength, it is manifest that the remaining one in like manner raises the

same and no more. Magnetick versoria also touched by an armed loadstone

turn with the same velocity and constancy towards the poles of the earth as

those magnetized by the same loadstone unarmed.

* * * * *

{88} CHAP. XIX.

Union with an armed Loadstone is stronger;

_hence greater weights are raised; but the_

coition is not stronger[176], but

_generally weaker_.

An armed magnet raises a greater weight, as is manifest to all; but a piece

of iron moves towards a stone at an equal, or rather greater, distance when

it * is bare, without an iron cap. This must be tried with two pieces of

iron of the same weight and figure at an equal distance, or with one and

the same versorium, the test being made first with an armed, then with an

unarmed loadstone, at equal distances.

* * * * *

[Illustration]

On the magnet, magnetick bodies also, and on the great magnet the earth a new physiology, demonstrated by many arguments & experiments · 第 38 / 110 题