s straight out.

{76} [Illustration]

The nearer the parts are to the aequinoctial, the more obliquely are
magneticals allured; but the parts nearer the poles appeal more directly,
at the poles quite straight. The principle of the turning of all
loadstones, of those which are round and those which are long, is the same,
but in the case of the long ones the experiment is easier. For in whatever
form they are the verticity exists, and there are poles; but on account of
bad and unequal form, they are often hindered by certain evils. If the
stone were long, the vertex is at the ends, not on the sides; it allures
more strongly at the vertex. For the parts bring together stronger forces
to the pole in right lines than oblique. So the stone and the earth conform
their magnetick motions by their nature.

* * * * *

CHAP. VII.

On the Potency of the Magnetick Virtue, and on
its nature capable of spreading out into an orbe.

From about a magnetical body the virtue magnetical is poured out on every
side around in an orbe; around a terrella; in the case of other shapes of
stones, more confusedly and unevenly. But yet there exists in nature no
orbe or permanent or essential virtue spread through the air, but a magnet
{77} only excites magneticks at a convenient distance from it. And as light
comes in an instant (as the opticians teach), so much more[165] quickly is
the magnetick vigour present within the limits of its strength; and because
its activity is much more subtile than light, and does not consent with a
non-magnetick substance, it has no intercourse with air, water, or any
non-magnetick; nor does it move a magnetick with any motion by forces
rushing upon it, but being present in an instant, it invites friendly
bodies. And as light strikes an object, so a loadstone strikes a magnetick
body and excites it. And just as light does not remain in the air above
vapours and effluvia, and is not reflected from those spaces, so neither is
the magnetick ray held in air or water. The appearances of things are
apprehended in an instant in mirrors and in the eye by means of light; so
the magnetick virtue seizes upon magneticks. Without the more intangible
and shining bodies, the appearances of things are not seized or reflected;
so without magnetical objects the magnetick power is not perceived, nor are
the forces thus conceived sent back again to the magnetick substance. In
this, however, the magne