g
versorium is moved forward from the aequator A to C, it catches on the
stone with its cusp (as if with a long extended wing), when the cusp
reaches to the parts about B, which produce a greater rotation than at C.
And the extremities of longer wires also and rods turn irregularly, just as
iron wires and balls of iron and other orbicular loadstones are likewise
turned about irregularly by a long non-orbicular loadstone. Just so
magneticks or iron bodies on the surface of a terrella ought not to have
too long an axis, but a very short one; so that they may make a declination
on the terrella truly and naturally proportionate to that on the earth. A
long versorium also close to a terrella with difficulty stands steady in a
horizontal direction on a right sphere, and, beginning to waver, it dips
immediately to one side, especially the end that was touched, or (if both
were touched) the one which felt the stone last.

* * * * *

{195} CHAP. V.

That declination does not arise from the attraction
of the loadstone, but from a disposing and
_rotating influence_.

In the universe of nature that marvellous provision of its Maker should be
noticed, whereby the principal bodies are restrained within certain
habitations and fenced in, as it were (nature controlling them). For this
reason the stars, though they move and advance, are not thrown into
confusion. Magnetical rotations also arise from a disposing influence,
whether in greater and dominating quantity, or in a smaller, and compliant
quantity, even though it be very small. For the work is not accomplished by
attraction, but by an incitation of each substance, by a motion of
agreement toward fixed bounds, beyond which no advance is made. For if the
versorium dipped by reason of an attractive force, then a terrella made
from a very strong magnetick stone would cause the versorium to turn toward
itself more than one made out of an average stone, and a piece of iron
touched with a vigorous loadstone would dip more. This, however, never
happens. Moreover, an iron snout placed on a meridian in any latitude does
not raise a spike more toward the perpendicular than the stone itself,
alone and unarmed; although when thus equipped, it plucks up and raises
many greater weights[234]. But if a loadstone be sharper toward one pole,
toward the other blunter, the sharp end or pole allures a magnetick needle
more strongly, the blunt, thick end makes it ro