On the variation of the declination.
Direction has been spoken of previously, and also * variation, which is
like a kind of dragging aside of the direction. Now in declination such
irregular motion is also noticed, when the needle dips beyond the proper
point or when sometimes it does not reach its mark. There is therefore a
variation of declination, being the arc of a magnetick meridian between the
true and apparent declination. For as, on account of terrestrial
elevations, magnetick bodies are drawn away from the true meridian, so also
the needle dips (its rotation being increased a little) beyond its genuine
position. For as variation is a deviation of the direction, so also, owing
to the same cause, there is some error of declination, though often very
slight. Sometimes, also, when there is no variation of direction in the
horizontal, there may nevertheless be variation of the declination; namely,
either when more vigorous parts of the earth crop out exactly meridionally,
_i.e._ under the very meridian; or when those parts are less powerful than
nature in general requires; or when the virtue is too much intensified in
one part, or weakened in another, just as one may observe in the vast
ocean. And this discrepant nature and varying effect may be easily seen in
certain parts of almost any round loadstone. Inæquality of power is
recognized in any part of a terrella by trial of the demonstration in chap.
2 of this book. But the effect is clearly demonstrated by the instrument
for showing declination in chap. 3 of this book.
* * * * *
{205} CHAP. XI.
On the essential magnetick activity sphærically
_effused._
Discourse hath often been held concerning the * poles of the earth and of
the stone, and concerning the æquinoctial zone; whilst lately we have been
speaking about the declining of magneticks toward the earth and toward the
terrella, and the causes of it. But while by various and complicated
devices we have laboured long and hard to arrive at the cause of this
declination, we have by good fortune found out a new and admirable (beyond
the marvels of all virtues magnetical) science of the orbes themselves. For
such is the power of magnetick globes, that it is diffused and extended
into orbes outside the body itself, the form being carried beyond the
limits of the corporeal substance; and a mind diligently versed in this
study of nature will find the definite causes of the motions and
revolutions. The same powers of a terrella exist also within the whole orbe
of its power; and these orbes at any distance from the body of the terrella
have in themselves, in proportion to their diameter and the magnitude of
their circumference, their own limits of influences, or points wherein
magnetick bodies rotate; but they do not look toward the same part of the
terrella or the same point at any distance from the same (unless they be on
the axis of the orbes and of the terrella); but they always tend to those
points of their own orbes, which are distant by similar arcs from the
common axis of the orbes. As, for example, in the following diagram, we
show the body of a terrella, with its poles and æquator; and also a
versorium on three other concentrick orbes around the terrella at some
distance from it. In these orbes (as in all those which we may imagine
without end) the magnetick body or versorium conforms to its own orbe in
which it is located, and to its diameter and poles and æquator, not to
those of the terrella; and it is by them and according to the magnitude of
their orbes that the magnetick body is governed, rotated, and directed, in
any arc of that orbe, both while the centre of the magnetick body stands
still, and also while it moves along. And yet we do not mean that the
magnetick forms and orbes exist in air or water or in any medium that is
not magnetical; as if the air or the water were susceptible of them, or
were induced by them; for the forms are only effused and really subsist
when magnetick substances are there; whence a magnetick body is laid hold
of within the forces and limits of the orbes; and within the orbes
magneticks {206} dispose magneticks and incite them, as if the orbes of
virtue were solid and material loadstones. For the magnetick force does not
pass through the whole medium or really exist as in a continuous body; so
the orbes are magnetick, and yet not real orbes nor existent by themselves.
_Diagram of motions in magnetick orbes._
[Illustration]
A B is the axis of the terrella and of the orbes, C D the æquator. On all
the orbes, as on the terrella, at the equator the versorium arranges itself
along the plane of the horizon; on the axis it everywhere looks
perpendicularly toward the centre; in the intermediate spaces E looks
toward D; and G looks toward H, not toward F, as the versorium L does on
the surface of the terrella. But as is the relation of L to F on the
surface of the terella, so is that of G to H on its orbe and of E to D on
its orbe; also all the rotations on {207} the orbes toward the termini of
the orbes are such as they are on the surface of the terrella, or toward
the termini of its surface. But if in the more remote orbes this fails
somewhat at times, it happens on account of the sluggishness of the stone,
or on account of the feebler forces due to the too great distance of the
orbes from the terrella.
_Demonstration._
Set upon the instrumental diagram described farther back [chap. 3] a plate
or stiff circle of brass or tin, on which may be described the magnetick
orbes, as in the diagram above; and in the middle let a hole be made
according to the size of the terrella, so that the plate may lie evenly on
the wood about the middle of the terrella on a meridional circle. Then let
a small versorium of the length of a barley-corn be placed on any orbe;
upon which, when it is moved to various positions on the same circle, it
will always pay regard to the dimensions of that orbe, not to those of the
stone; as is shown in the diagram of the effused magnetick forms.
While some assign occult and hidden virtues of substances, others a
property of matter, as the causes of the wonderful magnetical effects; we
have discovered the primary substantive form of globes, not from a
conjectural shadow of the truth of reasons variously controverted; but we
have laid hold of the true efficient cause, as from many other
demonstrations, so also from this most certain diagram of magnetick forces
effused by the form. Though this (the form) has not been brought under any
of our senses, and on that account is the less perceived by the intellect,
it now appears manifest and conspicuous even to the eyes through this
essential activity which proceeds from it as light from a lamp. And here it
must be noted that a magnetick needle, moved on the top of the earth or of
a terrella or of the effused orbes, makes two complete rotations in one
circuit of its centre, like some epicycle about its orbit.
* * * * *
{208} CHAP. XII.
Magnetick force is animate, or imitates life; and in
many things surpasses human life, while this is bound
_up in the organick body_.
A loadstone is a wonderful thing in very many experiments, and like a
living creature. And one of its remarkable virtues is that which the
ancients considered to be a living soul in the sky, in the globes and in
the stars, in the sun and in the moon. For they suspected that such various
motions could not arise without a divine and animate nature, immense bodies
turned about in fixed times, and wonderful powers infused into other
bodies; whereby the whole universe flourishes in most beautiful variety,
through this primary form of the globes themselves. The ancients, as
Thales, Heraclitus, Anaxagoras, Archelaus, Pythagoras, Empedocles,
Parmenides, Plato, and all the Platonists, and not only the older Greeks,
but the Egyptians and Chaldæans, seek for some universal life in the
universe, and affirm that the whole universe is endowed with life.
Aristotle affirms that not the whole universe is animate, but only the sky;
but he maintains that its elements are inanimate; whilst the stars
themselves are animate. We, however, find this life in globes only and in
their homogenic parts; and though it is not the same in all globes (for it
is much more eminent in the sun and in certain stars than in others of less
nobility) yet in very many the lives of the globes agree in their powers.
For each several homogenic part draws to its own globe in a similar manner,
and has an inclination to the common direction of the whole in the
universe; and the effused forms extend outward in all, and are carried out
into an orbe, and have bounds of their own; hence the order and regularity
of the motions and rotations of all the planets, and their courses, not
wandering away, but fixed and determined. Wherefore Aristotle concedes life
to the sphæres themselves and to the orbes of the heavens (which he
feigns), because they are suitable and fitted for a circular motion and
actions, and are carried along in fixed and definite courses. It is surely
wonderful, why the globe of the earth alone with its emanations is
condemned by him and his followers and cast into exile (as senseless and
lifeless), and driven out of all the perfection of the excellent universe.
It is treated as a small corpuscle in comparison with the whole, and in the
numerous concourse of many thousands it is obscure, disregarded, and
unhonoured. {209} With it also they connect the kindred elements, in a like
unhappiness, wretched and neglected. Let this therefore be looked upon as a
monstrosity in the Aristotelian universe, in which everything is perfect,
vigorous, animated; whilst the earth alone, an unhappy portion, is paltry,
imperfect, dead, inanimate, and decadent. But on the other hand Hermes,
Zoroaster, Orpheus, recognize a universal life. We, however, consider that
the whole universe is animated, and that all the globes, all the stars, and
also the noble earth have been governed since the beginning by their own
appointed souls and have the motives of self-conservation. Nor are there
wanting, either implanted in their homogenic nature or scattered through
their homogenic substance, organs suitable for organic activity, although
these are not fashioned of flesh and blood as animals, or composed of
regular limbs, which are also hardly perceptible in certain plants and
vegetables; since regular limbs are not necessary for all life. Nor can any
organs be discerned or imagined by us in any of the stars, the sun, or the
planets, which are specially operative in the universe; yet they live and
imbue with life the small particles in the prominences on the earth. If
there be anything of which men can boast, it is in fact life, intelligence;
for the other animals are ennobled by life; God also (by whose nod all
things are ruled) is a living soul. Who therefore will demand organs for
the divine intelligences, which rise superior to every combination of
organs and are not restrained by materialized organs? But in the several
bodies of the stars the implanted force acts otherwise than in those divine
existences which are supernaturally ordained; and in the stars, the sources
of things, otherwise than in animals; in animals again otherwise than in
plants. Miserable were the condition of the stars, abject the lot of the
earth, if that wonderful dignity of life be denied to them, which is
conceded to worms, ants, moths, plants, and toadstools; for thus worms,
moths, grubs would be bodies more honoured and perfect in nature; for
without life no body is excellent, valuable, or distinguished. But since
living bodies arise and receive life from the earth and the sun, and grass
grows on the earth apart from any seeds thrown down (as when soil is dug up
from deep down in the earth, and put on some very high place or on a very
high tower, in a sunny spot, not so long after various grasses spring up
unbidden) it is not likely that they can produce what is not in them; but
they awaken life, and therefore they are living. Therefore the bodies of
the globes, as important parts of the universe, in order that they might be
independent and that they might continue in that condition, had a need for
souls to be united with them, without which there can be neither life, nor
primary activity, nor motion, nor coalition, nor controlling power, nor
harmony, nor endeavour, nor sympathy; and without which there would be no
generation {210} of anything, no alternations of the seasons, no
propagation; but all things would be carried this way and that, and the
whole universe would fall into wretchedest Chaos, the earth in short would
be vacant, dead, and useless. But it is only on the superficies of the
globes that the concourse of living and animated beings is clearly
perceived, in the great and pleasing variety of which the great
master-workman is well pleased. But those souls which are restrained within
a kind of barrier and in prison cells, as it were, do not emit immaterial
effused forms outside the limits of their bodies; and bodies are not moved
by them without labour and waste. They are brought and carried away by a
breath; and when this has calmed down or been suppressed by some untoward
influence, their bodies lie like the dregs of the universe and as the
refuse of the globes. But the globes themselves remain and continue from
year to year, move, and advance, and complete their courses, without waste
or weariness. The human soul uses reason, sees many things, inquires about
many more; but even the best instructed receives by his external senses (as
through a lattice) light and the beginnings of knowledge. Hence come so
many errors and follies, by which our judgments and the actions of our
lives are perverted; so that few or none order their actions rightly and
justly. But the magnetick force of the earth and the formate life or living
form of the globes, without perception, without error, without injury from
ills and diseases, so present with us, has an implanted activity, vigorous
through the whole material mass, fixed, constant, directive, executive,
governing, consentient; by which the generation and death of all things are
carried on upon the surface. For, without that motion, by which the daily
revolution is performed, all earthly things around us would ever remain
savage and neglected, and more than deserted and absolutely idle. But those
motions in the sources of nature are not caused by thinking, by petty
syllogisms, and theories, as human actions, which are wavering, imperfect,
and undecided; but along with them reason, instruction, knowledge,
discrimination have their origin, from which definite and determined
actions arise, from the very foundations that have been laid and the very
beginnings of the universe; which we, on account of the infirmity of our
minds, cannot comprehend. Wherefore Thales, not without cause (as Aristotle
relates in his book _De Anima_), held that the loadstone was animate, being
a part and a choice offspring of its animate mother the earth.
* * * * *
{211} [Illustration]