be either true or near it, as great Allowances have been made for the
Ignorance of the Ages in which they were taken, and the Inaccuracy
of the Instruments, we may naturally conclude, that these Stars must
have a Motion; and if they move, as has been before observed, the Sun
must also; hence he cannot now be in the original Plane of the Earth's
annual Direction, or at least in the same identical Place he was at
first possessed of: And if so, the Stars must also have the like
Motion, though in different Directions, and all may thus be governed by
the same impulsive Power.
To illustrate this primitive Motion of the Stars, and at the same time
to show that the Variety which appears in the Quantity of Motion can be
no Objection to it,
See PLATE XVIII. _Fig._ 2.
Where A represents the Eye of an Observer, and B, E, F, H, various
Systems, moving in different Directions thro' the mundane Space; it
is evident that the Sphere B, having moved from C, and that of E, not
having appeared to move at all, there must be a sensible Change in the
new Position of these two Systems to one another, and so of the rest;
and tho' the apparent Motion of H, be much more than that of F, from
the Point A, yet from C, they will appear less different, and from B,
they will appear nearly equal. And farther, as the Direction from H, is
in the Line I, H, and that of F, in the Line K, G, those two Systems
will appear to approximate, and the Magnitude of the Star in the first
will be increased, and in the latter diminished. Thus, many of the
Stars in the oldest Catalogues, which were said to be of the second
Magnitude, are now become of the first, and several of the first are
now judged to be of the second, &c.
But as this apparent Motion of the Stars at the Earth, must, from its
Nature, be very small, so as scarce to be discovered in some of them in
less than an Age, with any Instrument by the nicest Observer, I judge
it will be extremely proper in this Place to propose some Method, by
which, in process of Time, the Truth of the Theory may be ascertained.
The Way I think most likely to succeed is this.
PLATE XIX.
Is a Plan of the principal Stars that form the Pleiades, correctly
taken by a Combination of Triangles, as in the Figure, from whence it
will naturally follow, all the whole Form being comprehended in much
less than one Degree. That the most minute local Motion in any one of
those Stars in a very few Years, will be made sensible to an Eye at
the Earth. For Instance, if any of the Stars that form the Letter A,
or T, within the Term of ten or twenty Years, be found in the least
to deviate from the Lines of their present Position and Direction,
it will be evident beyond a Contradiction, that they have a Motion
amongst themselves, and since at such a Distance they cannot possibly
be affected by the Earth, it must be a Motion of their own; and thus
if any one can be proved, to change its Situation, with regard to the
rest, we can have no new Difficulty in concluding that they all may do
the same.
Thus if any of the regular Triangles M B Z, Z P H, A Z M, Y A Γ, or Π
Ο I, &_c._ in due Time be carefully noted, we may venture to say with
great Safety, that the thousandth Part of a Degree will be plainly
discovered.
PLATE XX.
Is a true Plan and Combination of the principal Stars that form the
Persedes, in which other Observations may be made in a different Part
of the Heavens, and perhaps with an Opportunity of being still more
exact, the Areas of these Triangles, particularly that of Θ I K, and
those of ρ and δ, being much less than the former, where the least
Alteration possible must render them sensibly distorted. But here it
must be considered, that the real Motion of the Stars, as well as their
apparent, may be, and in all Likelihood, is extreamly slow, for the
most minute, visible, local Motion, will answer all the Purposes we
know in Nature, and the greatest seems to be that of the projectile, or
centrifugal Force, which not only preserves them in their Orbits, but
prevents them from rushing all together, by the common universal Law of
Gravity, which otherwise, as a finite Distribution of either regular or
irregular Bodies, they must at length do by Necessity.
[Illustration: Plate XIX.]
[Illustration: Plate XX.]
I must now inform you, that the above Observations were compleated in
the Autumn Season, 1747, and were taken by myself; the Letters A, T, in
_Plate_ XIX, and the W in the XXth, as you may see, having a very near
Resemblance, or Similitude, to the Order these Stars are found to be
in, together with the _Greek_ Alphabet, I judged necessary, by way of
_Asterism_ and _Nomenclatura_, in case such should be wanted, as _Data_
in future Discoveries.
I come now to the principal Point in Question, which is to find a
regular Disposition of the Stars amongst themselves, which will
naturally solve both their general and particular Phænomena, especially
the _Nebula_ and _Milky Way_.
_I am now_, &c.
[Illustration]
LETTER the SEVENTH.
_The Hypothesis, or Theory, fully explained and demonstrated, proving
the sidereal Creation to be finite._
_SIR_,
I know you are an Enemy to all Sorts of Schemes where they are not
absolutely necessary, and may possibly be avoided; and for that
Reason I have purposely omitted many geometrical Figures, and other
Representations in this Work, which might have been inserted and in
some Places, especially here I might have introduced Diagrams, perhaps
more explicit than Words; but as you have frequently observed, they
are only of Use to the few Learned, and contribute more to the taking
away the little Ideas and Knowledge the more ignorant Many may be
endued with, by a prejudicial Impression of imperfect Images, rather
than the adding any new Light to their Understanding, I have purposely
avoided, as much as possible, both here and every where, all such
complex Diagrams as might be in Danger of betraying any the least
such conscious Diffidence in you, arising from the Want of a proper
_Precognita_ in the Sciences.
This Imperfection, much to be lamented, as greatly to the Disadvantage
of all mathematical Reasoning, I would willingly always prevent, in my
Readers, and to chuse in my Friend; I shall therefore content myself
with referring you to a few orbicular Figures, concave and convex, as
may best suggest to your Fancy the simplest Way, a just Idea of the
Hypothesis I have fram'd, and naturally enough I hope, render my Theory
so intelligible, as to help you sufficiently to conceive the Solution
aimed at, of the important Problem I have attempted.
As I have said before, we cannot long observe the beauteous Parts of
the visible Creation, not only those of this World on which we live,
but also the Myriads of bright Bodies round us, with any Attention,
without being convinced, that a Power supreme, and of a Nature unknown
to us, presides in, and governs it.
The Course and Frame of this vast Bulk, display
A Reason and fix'd Law, which all obey.
Sher. Manilius.
And notwithstanding the many wonderful Productions of Nature in this
our known Habitation, yet the Earth, when compared with other Bodies of
our own System, seems far from being the most considerable in it; and
it appears not only very possible, but highly probable, from what has
been said, and from what we can farther demonstrate, that there is as
great a Multiplicity of Worlds, variously dispersed in different Parts
of the Universe, as there are variegated Objects in this we live upon.
Now, as we have no Reason to suppose, that the Nature of our Sun is
different from that of the rest of the Stars; and since we can no way
prove him superior even to the least of those surprising Bodies, how
can we, with any Shew of Reason, imagine him to be the general Center
of the whole, _i. e._ of the visible Creation, and seated in the Center
of the mundane Space? This, in my humble Opinion, is too weak even for
Conjecture, their apparent Distribution, and [AO]irregular Order argue
so much against it.
[Footnote AO: See the Zodaical Constellations, you'll find that in
some Signs there are several Stars of the first, second, and third
Magnitude, and in many others none of these at all.]
The Earth indeed has long possessed the chief Seat of our System, and
peaceably reigned there, as in the Center of the Universe for many Ages
past; but it was human Ignorance, and not divine Wisdom, that placed it
there; some few indeed from the Beginning have disputed its Right to
it, as judging it no way worthy of such high Eminence. Time at length
has discovered the Truth to every body, and now it is justly displaced
by the united Consent of all its Inhabitants, and instead of being
thought the most majestick of all Nature's lower Works, now rather
disgraces the Creation, so much it is reduced in its present State from
what it had Reason to expect in the former.
Now it is no longer the only terrestrial Globe in the Universe, but
is proved to be one of the least Planets of the solar System, and
surprizingly inferior to some of its Fellow Worlds. The Sun, or rather
the System, has almost as long usurped the Center of Infinity, with as
little Pretence to such Pre-heminence; but now, Thanks to the Sciences,
the Scene begins to open to us on all Sides, and Truths scarce to
have been dreamt of, before Persons of Observation had proved them
possible, invades our Senses with a Subject too deep for the human
Understanding, and where our very Reason is lost in infinite Wonders.
How ought this to humble every Mind susceptible of Reason!
In this Place, I believe, you will pardon a Digression; which,
in Answer to Part of your last Letter, I judge will not be very
impertinent, tho' perhaps just here I cannot so well justify it.
Your late Conversation with our Friend Mr. * * *, I am perswaded, must
have been very entertaining; but I cannot help thinking his Reflections
upon the Wonders of Nature and the Wisdom of Providence, though I must
allow them all to be very just and curious, instead of elevating the
Mind to the Pitch he would have it, rather as considered above, depress
it below the proper, nay I might say necessary, Standard of human Ideas.
This, probably, you'll say is an odd Turn, and may want some
Explanation, since every Object in the Chain of Nature, must of Force
be granted, a Subject worthy of our Speculations, being all together
made, as in the Maximum of Wisdom: But what I mean is this, since
nothing is more natural for Beings in every State in search after their
own Advantages, and the Enlargement of their Ideas to look upward, sure
it may be presumed, that Time may be mispent, if not lost in inspecting
too narrowly Things so little benefical in States below us; as Mr.
_Pope_ says,
Why has not Man a microscopic Eye?
For this plain Reason, Man is not a Fly.
Say what the Use, were finer Opticks given,
To inspect a Mite, not comprehend the Heav'n.
_Essay on Man._
Amusement alone can never be supposed to be the sole End of human Life,
where even true Happiness is a Thing we rather taste than enjoy. The
Mind we find capable of much more rational Pleasure than can possibly
fall within the Reach of human Power, either to promise or procure it;
but then this very Defect in our present State of Existence affords us
no less than a moral Assurance, that some where in a future, we may, if
we please, be entitled to the very _Plenum_ of all Enjoyments.
The peculiar Business then of the human Mind naturally precedes its
Amusements, as evidently ordained to soar above all the inferior Beings
of this World; and however our Natures may, thro' Indolence, or thro'
Ignorance, degenerate, that of the Man can never be supposed to sink
into the Mole.
The properest Way then sure for Men to preserve their Pre-heminence
over the Brute Creation, is to make use of that Reason and Reflection,
which so manifestly distinguishes their natural Superiority. A right
Application of which, must of course then direct us to a forward,
rather than a backward Search in the vast visible Chain of our
Existence, which clearly connects all Beings and States as under the
Direction of one supreme Agent.
This is all I would have understood by the foregoing Position, which,
in one Word, implies no more than that the sublime Philosophy ought in
all Reason to be preferred to the Minute; but I hope you will not infer
from this my seeming Partiality for the celestial Sciences, that I mean
to insinuate, that the Study of terrestrial Physicks is not a rational
Amusement.
Mr. ***, you say, seems to lament the Taste of Mankind in general much
in the same Degree as you do his I readily grant you; a Man who can
talk so well upon an Ant, might make a more entertaining Discourse upon
the Eagle; but I beg his Pardon, and though we are all too ready, and
most apt to condemn all such Pleasures as vain or trifling, which we
have no Share in, or Taste for ourselves; yet I don't think it follows,
that those ingenious Labours of his are useless. The Pleasures arising
from natural Philosophy are all undoubtedly great ones, whether we
consider Nature in her highest, or in her lowest Capacity; the Beauties
of the Creation are every Day varied to us below, as much they are
every Night above, and in both Cases, through every Object, the Creator
shines so manifest, that we may justly consider him every where smiling
full in the Face of all his Creatures, commanding as it were an awful
Reverence, and Respect, due not only to his Omnipotency, but also
to his infinite Goodness and endless Indulgencies. This is the only
Return our Gratitude can make for all those Blessings he daily bestows
upon us, and to this great Author of her Laws; Nature herself cries
aloud through Myriads of various Objects, and after her own expressive
and peculiar Manner, seems to command us with an attractive Grace,
to observe her Sovereign, and admire his Wisdom. The Majesty, Power,
and Dominion of God is best displayed in the external Direction of
Things, his Wisdom and visible Agency in the internal: Hence, by proper
Objects, selected from both, attended with just Reflections, we may
certainly raise our Ideas almost to the Pitch of Immortals; but how
far the human Imagination may possibly go, or how much Minds like ours
may be improved, is a Question not easily determined; but as natural
Knowledge evidently increases daily, and astronomical Enquiries are
the most capable of opening our Minds, and enlarging our Conception,
of consequence they must be most worthy our Attention of all other
Studies. But of this I have said enough, and think it is now more than
Time to attempt the remaining Part of my Theory.
When we reflect upon the various Aspects, and perpetual Changes of
the Planets, both with regard to their[AP] heliocentric and geocentric
Motion, we may readily imagine, that nothing but a like eccentric
Position of the Stars could any way produce such an apparently
promiscuous Difference in such otherwise regular Bodies. And that in
like manner, as the Planets would, if viewed from the Sun, there may be
one Place in the Universe to which their Order and primary Motions must
appear most regular and most beautiful. Such a Point, I may presume, is
not unnatural to be supposed, altho' hitherto we have not been able to
produce any absolute Proof of it. See _Plate_ XXV.
[Footnote AP: Not to mention their several Conjunctions and Apulces to
fixed Stars, &_c._ see the State of the Heavens in 1662, _December_
the first, when all the known Planets were in one Sign of the Zodiac,
_viz._ _Sagittarius_.]
This is the great Order of Nature, which I shall now endeavour to
prove, and thereby solve the Phænomena of the _Via Lactea_; and in
order thereto, I want nothing to be granted but what may easily be
allowed, namely, that the _Milky Way_ is formed of an infinite Number
of small Stars.
Let us imagine a vast infinite Gulph, or Medium, every Way extended
like a Plane, and inclosed between two Surfaces, nearly even on both
Sides, but of such a Depth or Thickness as to occupy a Space equal to
the double Radius, or Diameter of the visible Creation, that is to
take in one of the smallest Stars each Way, from the middle Station,
perpendicular to the Plane's Direction, and, as near as possible,
according to our Idea of their true Distance.
But to bring this Image a little lower, and as near as possible
level to every Capacity, I mean such as cannot conceive this kind of
continued Zodiac, let us suppose the whole Frame of Nature in the
Form of an artificial Horizon of a Globe, I don't mean to affirm that
it really is so in Fact, but only state the Question thus, to help
your Imagination to conceive more aptly what I would explain[AP].
_Plate_ XXIII. will then represent a just Section of it. Now in this
Space let us imagine all the Stars scattered promiscuously, but at
such an adjusted Distance from one another, as to fill up the whole
Medium with a kind of regular Irregularity of Objects. And next let
us consider what the Consequence would be to an Eye situated near the
Center Point, or any where about the middle Plane, as at the Point A.
Is it not, think you, very evident, that the Stars would there appear
promiscuously dispersed on each Side, and more and more inclining to
Disorder, as the Observer would advance his Station towards either
Surface, and nearer to B or C, but in the Direction of the general
Plane towards H or D, by the continual Approximation of the visual
Rays, crowding together as at H, betwixt the Limits D and G, they must
infallibly terminate in the utmost Confusion. If your Opticks fails
you before you arrive at these external Regions, only imagine how
infinitely greater the Number of Stars would be in those remote Parts,
arising thus from their continual crowding behind one another, as all
other Objects do towards the Horizon Point of their Perspective, which
ends but with Infinity: Thus, all their Rays at last so near uniting,
must meeting in the Eye appear, as almost, in Contact, and form a
perfect Zone of Light; this I take to be the real Case, and the true
Nature of our _Milky Way_, and all the Irregularity we observe in it
at the Earth, I judge to be intirely owing to our Sun's Position in
this great Firmament, and may easily be solved by his Excentricity, and
the Diversity of Motion that may naturally be conceived amongst the
Stars themselves, which may here and there, in different Parts of the
Heavens, occasion a cloudy Knot of Stars, as perhaps at E.
[Illustration: Plate XXI.]
[Illustration: Plate XXII.]
But now to apply this Hypothesis to our present Purpose, and reconcile
it to our Ideas of a circular Creation, and the known Laws of orbicular
Motion, so as to make the Beauty and Harmony of the Whole consistent
with the visible Order of its Parts, our Reason must now have recourse
to the Analogy of Things. It being once agreed, that the Stars are in
Motion, which, as I have endeavoured in my last Letter to shew is not
far from an undeniable Truth, we must next consider in what Manner they
move. First then, to suppose them to move in right Lines, you know is
contrary to all the Laws and Principles we at present know of; and
since there are but two Ways that they can possibly move in any natural
Order, that is, either in right Lines, or in Curves, this being one,
it must of course be the other, _i. e._ in an Orbit; and consequently,
were we able to view them from their middle Position, as from the Eye
seated in the Center of _Plate_ XXV. we might expect to find them
separately moving in all manner of Directions round a general Center,
such as is there represented. It only now remains to shew how a Number
of Stars, so disposed in a circular Manner round any given Center, may
solve the Phænomena before us. There are but two Ways possible to be
proposed by which it can be done, and one of which I think is highly
probable; but which of the two will meet your Approbation, I shall not
venture to determine, only here inclosed I intend to send you both. The
first is in the Manner I have above described, _i. e._ all moving the
same Way, and not much deviating from the same Plane, as the Planets
in their heliocentric Motion do round the solar Body. In this Case the
primary, secondary, and tertiary constituent Orbits, &_c._ framing the
Hypotheses, are represented in _Plate_ XXII, and the Consequence of
such a Theory arising from such an universal Law of Motion in _Plate_
XXIII. where B, D denotes the local Motion of the Sun in the true
_Orbis Magnus_, and E, C that of the Earth in her proper secondary
Orbit, which of course is supposed, as is shewn in the Figure to change
its sidereal Positions, in the same Manner as the Moon does round the
Earth, and consequently will occasion a kind of Procession, or annual
Variation in the Place of the Sun, not unlike that of the Equinoxes, or
Motion of all the Stars together, from West to East round the Ecliptic
Poles, and probably may in some Degree be the Occasion of it. This
Angle is represented, but much magnified, by the Lines F, C, G, and the
Unnaturalness, or Absurdity of a right Line Motion of the Sun by the
Line I, H.
The second Method of solving this Phænomena, is by a spherical Order of
the Stars, all moving with different Direction round one common Center,
as the Planets and Comets together do round the Sun, but in a kind of
Shell, or concave Orb. The former is easily conceived, from what has
been already said, and the latter is as easy to be understood, if you
have any Idea of the Segment of a Globe, which the adjacent Figures,
will, I hope, assist you to. The Doctrine of these Motions will perhaps
be made very obvious to you, by inspecting the following Plates.
PLATE XXIV.
Is a Representation of the Convexity, if I may call it so, of the
intire Creation, as a universal Coalition of all the Stars consphered
round one general Center, and as all governed by one and the same Law.
PLATE XXV.
Is a centeral Section of the same, with the Eye of Providence seated in
the Center, as in the virtual Agent of Creation.
PLATE XXVI.
Represents a Creation of a double Construction, where a superior Order
of Bodies C, may be imagined to be circumscribed by the former one A,
as possessing a more eminent Seat, and nearer the supream Presence, and
consequently of a more perfect Nature. Lastly,
PLATE XXVII.
Represents such a Section, and Segments of the same, as I hope will
give you a perfect Idea of what I mean by such a Theory.
_Fig._ 1. is a corresponding Section of the Part at A, in _Fig._ 2.
whose versed Sine is equal to half the Thickness of the starry Vortice
A C, or B A. Now I say, by supposing the Thickness of this Shell, 1.
you may imagine the middle Semi-Chord A D, or A E, to be nearly 6; and
consequently thus in a like regular Distribution of the Stars, there
must of course be at least three Times as many to be seen in this
Direction of the Sine, or Semi-chord A E, itself, than in that of the
semi-versed Sine A C, or any where near the Direction of the Radius of
the Space G. Q. E. D.
[Illustration: Plate XXIII.]
[Illustration: Plate XXIV.]
[Illustration: Plate XXV.]
[Illustration: Plate XXVI.]
[Illustration: Plate XXVII.]
[Illustration: Plate XXVIII.]
[Illustration: Plate XXIX.]
But we are not confined by this Theory to this Form only, there may be
various Systems of Stars, as well as of Planets, and differing probably
as much in their Order and Distribution as the Zones of _Jupiter_ do
from the Rings of _Saturn_, it is not at all necessary, that every
collective Body of Stars should move in the same Direction, or after
the same Model of Motion, but may as reasonably be supposed as much to
vary, as we find our Planets and Comets do.