of perfect Spheres, all variously inclined, direct and retrograde;
others again, as the primary Planets do, in a general Zone or Zodiack,
or more properly in the Manner of _Saturn's_ Rings, nay, perhaps Ring
within Ring, to a third or fourth Order, as shewn in _Plate_ XXVIII.
nothing being more evident, than that if all the Stars we see moved
in one vast Ring, like those of _Saturn_, round any central Body, or
Point, the general Phænomena of our Stars would be solved by it; see
_Plate_ XXIX. _Fig._ 1. and 2. the one representing a full Plane of
these Motions, the other a Profile of them, and a visible Creation at
B and C, the central Body A, being supposed as _incognitum_, without
the finite View; not only the Phænomena of the _Milky Way_ may be
thus accounted for, but also all the cloudy Spots, and irregular
Distribution of them; and I cannot help being of Opinion, that could
we view _Saturn_ thro' a Telescope capable of it, we should find his
Rings no other than an infinite Number of lesser Planets, inferior to
those we call his Satellites: What inclines me to believe it, is this,
this Ring, or Collection of small Bodies, appears to be sometimes very
excentric, that is, more distant from _Saturn's_ Body on one Side than
on the other, and as visibly leaving a larger Space between the Body
and the Ring; which would hardly be the Case, if the Ring, or Rings,
were connected, or solid, since we have good Reason to suppose, it
would be equally attracted on all Sides by the Body of _Saturn_, and by
that means preserve every where an equal Distance from him; but if they
are really little Planets, it is clearly demonstrable from our own in
like Cases, that there may be frequently more of them on one Side, than
on the other, and but very rarely, if ever, an equal Distribution of
them all round the _Saturnian_ Globe.
How much a Confirmation of this is to be wished, your own Curiosity may
make you judge, and here I leave it for the Opticians to determine.
I shall content myself with observing that Nature never leaves us
without a sufficient Guide to conduct us through all the necessary
Paths of Knowledge; and it is far from absurd to suppose Providence may
have every where throughout the whole Universe, interspersed Modules of
every Creation, as our Divines tell us, Man is the Image of God himself.
Thus, Sir, you have had my full Opinion, without the least Reserve,
concerning the visible Creation, considered as Part of the finite
Universe; how far I have succeeded in my designed Solution of the _Via
Lactea_, upon which the Theory of the Whole is formed, is a Thing will
hardly be known in the present Century, as in all Probability it may
require some Ages of Observation to discover the Truth of it.
It remains that I should now give you some Idea of Time and Space; but
this will afford Matter sufficient for another Letter.
_I am_, &c.
[Illustration]
LETTER THE EIGHTH.
_Of Time and Space, with regard to the known Objects of Immensity and
Duration._
_SIR_,
The Opportunity you gave me in your last Visit, of shewing you my
general Scheme of the Universe, I find, besides the Pleasure it then
gave, is now attended with many useful Advantages.
I now not only hope to be better understood for the future, but have
reason to expect what I now write will merit your Attention more, and
have some Title to your Approbation. The Ideas I have fram'd of Time
and Space, will now more gradually fill your Imagination both with
Wonder and Delight, before they can arise so high as to be lost in
an Eternity and the Infinity of Space. And I am fully perswaded your
farther Inquiries into these vast Properties of the Deity, will here
be answered intirely to your Satisfaction. You must allow me now to
be in some measure a Judge of what I think will please you most, from
the Observations you have made upon my general System, or otherwise
you would have reason to think me perhaps too presuming: But I flatter
myself the great Difficulty is now over; and what remains to be said,
will all so naturally follow from what has gone before, that this Letter,
I guess, will go near to furnish you with all the Ideas you wish to
form upon the Subject. To what you have said of my having left out my
own Habitation in my Scheme of the Universe, having travell'd so far
into Infinity as both to lose sight of, and forget the Earth, I think I
may justly answer as _Aristotle_ did when _Alexander_, looking over a
Map of the World, enquir'd of him for the City of _Macedon_; 'tis said
the Philosopher told the Prince, That the Place he sought for was much
too small to be there taken Notice of, and was not without sufficient
Reason omitted.
The System of the Sun compar'd but with a very minute Part of the
visible Creation, takes up so small a Portion of the known Universe,
that in a very finite View of the Immensity of Space, I judg'd the
Seat of the Earth to be of very little Consequence, could I have
possibly represented it, as not only being one of the smallest Objects
in our Regions, but in a manner infinitely less than even her own
annual Orbit, and had nothing to do with my main Design, which was to
represent all our planetary Worlds as one collective Body, and begin
my comparative Scale of Magnitude from the Sun only and his Sphere of
activity; as the smallest Object I could with any Propriety pretend to
express in such a Plan.
In some Measure to convince you that I have committed no Error in
this, I will try by some less mathematical Method than that of meer
Numbers, to imprint an Idea in your Mind of the true Extent of the
solar System, and the Magnitude of all its moving Bodies, by natural
Objects most familiar to your Senses. When we endeavour to form any
Idea of Distance, Magnitude, or Duration, by Numbers only, we so soon
exceed the Limits of Conception, that this way we find our Faculties of
reasoning as finite as our Senses; and no doubt 'tis right it should be
so, Providence, as it were, having ordain'd that the first should only
attend the last, in such an adequate Degree to a determin'd Distance;
but what Distance or Degree of Knowledge is destin'd to human Nature,
none but the Power that gave it can tell. 'Tis certain that beyond the
third or fourth Place of our Nomenclator, we receive but very faint
Impressions of the thing exprest, and can frame scarce any Notion at
all of either Number, Distance, or Magnitude, signified beyond it:
Hence Astronomers are frequently oblig'd to have recourse to mixt
Ideas, and make Things of different Natures and Properties assist each
other, to excite more adequate Ideas of what they would have conceived.
Thus to express immense Distances and Magnitude, they frequently apply
themselves to Time and Motion; and _vice versa_, to signify a long
Duration, they have often recourse to Distance and Matter, removing, in
Imagination, Worlds of Sand, Grain after Grain, to some remote known
Region.
_Hesiod_,[AQ] to express his Idea of the Distance from his highest
Heaven to Earth, and from Earth to Hell, or _Tartarus_, supposes an
Anvil to be let fall from one to the other, which he says in nine
natural Days would reach the Earth from Heaven, and in the same time
would fall from the Earth to Hell. [AR]_Homer_ makes his _Vulcan_ fall
from Heaven to the Island of _Lemnos_ in much less Time, not exceeding
one full artificial Day.
[Footnote AQ:
From the high Heaven a brazen Anvil cast,
Nine Nights and Days in rapid Whirls would last,
And reach the Earth the Tenth, whence strongly hurl'd;
The same the Passage to th' infernal World.
Cooke.
]
[Footnote AR:
Hurl'd headlong downward from th' etherial Height;
Toss'd all the Day in rapid Circles round,
Nor till the Sun descended touch'd the Ground.
Pope.
]
Modern Astronomers have made use of the swiftest Velocity of a
Cannon-Ball as continued thro' the Space they would so describe, and
in this Light, the Distance to the Sun has been by many compar'd to
twenty-five Years Motion of a Cannon-Ball, supposing it to travel at
the Rate of 100 Fathom in a Moment, _i. e._ _the Pulse of an Artery_;
and that a Journey so performed to one of the nearest fix'd Stars,
would take the same Body at least 100,000 Years before it could arrive
there. But the Method I have chose to convey my Ideas of the Magnitude
of the planetary Bodies, and the Extent of the visible Creation to you,
I am willing to hope you will find still more familiar, comprehensive,
and easy: And it only depends upon your Remembrance of a very few known
Objects, and their neighbouring Distances, which may be presumed you
are, or have been, very well acquainted with. You have not only very
lately but very often been in _London_, and must, I think, retain some
Idea of the Dome of St. _Paul's_, tho' I own I ought not to be sorry
if you should chance to have forgot it, provided it might prove a
Means of making your Visits more frequent. The Diameter of the Dome of
this Church is 145 Feet: Now if you can imagine this to represent the
Surface of the Sun, a spherical Body 18 Inches diameter, will justly
represent the Earth in like Proportion; and another of only five Inches
diameter, will represent the Moon. The Truths of these Proportions I
have shewn in my _Clavis Cœlestis_; and the Reason why I have here fixt
upon the Dome of this Church for my first Object of Comparison, will
naturally appear from what follows.
From the Magnitude of the Earth on which we live, as from a known Scale
with respect to its Parts compar'd with our own Bodies, we naturally
frame our first Ideas of Extent, and fix our Rationale of Remoteness;
by which we are sufficiently enabled to judge of all other sensible
Distances within one finite View. And hence by the undoubted Principles
of Geometry, having first given the Measurement of the Earth in any
known Proportion with any other Quantity most familiar to our Senses,
and the Angle of Appearance, or Parallax to any perceivable Object, we
can easily find in homogenial Parts its true Distance from the Eye. And
thus allowing for some small tho' unavoidable Errors, that may possibly
arise from the Difficulties of Observation (especially small Angles and
minute Quantities) we can always determine to a sufficient, and very
frequently to a just Exactness, the relative Distance of all visible
Bodies, remote or near, such as the Planets, Comets, and the Sun.
[AS]In this Manner Astronomers having procur'd a comparative Standard,
reduc'd to some known Measure, as _English_ Miles, Leagues, Semi-Orbs
or Orbits, with all the Force of analogical Reasoning, clearly can
demonstrate the Place and Distance of any Object within the Reach of
Observation, and judge of Distances almost indefinite.
[Footnote AS: Parallax is the changeable Position of Bodies to
different Situations of the Eye. First having found the Quantity of a
Degree (_i. e._ a 60th Part of the Circumference) upon the Earth's
Surface, _Aratosthenes_ discover'd that the Magnitude of the whole was
easily known; and then from the Moon's horizontal Parallax having given
the Radius of the Earth, the Distance of the Moon is soon determined;
next by the menstrual Parallax of the Lunar Orbit, the Distance of the
Sun is found; and by the Elongation of the inferior Planets, their
mutual Distance from each other; and, lastly, from the annual Parallax
of the Earth's Orbit, all the other Orbits of the superior Planets are
easily found.]
PLATE XXX.
Will help you to very correct Ideas of the real Magnitude of the
Globe of the Earth, compar'd with the just Extent of the Island of
_Great-Britain_, which you will find with _Ireland_, and the rest
of its Islands, seated near the Center of the Projection. This as
a Standard will enable you to judge of all other Distances more
perfectly; and first I shall consider that of the Sun.
The Sun is found to be mean distant from the Earth nearly 81 Millions
of Miles, or 6877,5 Diameters of the Earth; and _Saturn_, the remotest
Planet from him is at his greatest Distance from us about 858 Millions
of Miles: Yet these Distances are but the beginning of Space, and only
serve to open our Ideas for farther Search.
The great Comet of 1680, as I have some where said before, was found
to move in so vast an excentrick Orbit, that in its aphelion Point it
would be 14,4 Times as far from the Sun, as the Orbit of _Saturn_, and
hence at least eleven thousand and two hundred Millions of Miles from
us. Now since the wise Creator hath so dispos'd all the independent
Parts of the Creation, such as the several Systems of primary and
secondary Planets, &_c._ at so great a Distance from each other,
that the Laws of any one in no wise shall interfere, disturb, or
interrupt the Principles of another; this Comet, which we can easily
prove belong'd to our own Sun, we may well imagine came not near any
other; and tho' at that vast Distance from the solar Body, yet still
there must have remain'd a Space sufficient to divide or seperate the
sensible activity of neighbouring Systems, that they may not rush upon
each other. Hence we may reasonably suppose, that the nearest Star can
be no nearer than a triple Radius of its active Sphere; and provided
they are all in regular Order, and much of the same Magnitude with one
another (which no Arguments can possibly contradict) this Radius we
may justly make 2000 times the Distance of our Earth. For admitting
the utmost Limits of the Sun's Attraction to exceed this Sphere of
the Comets, as far as the Sphere of the Comets exceeds that of the
Planets, which is nearly 14,4 times, the Radius of the solar System
will be extended every way 200 Radius's of the Orbit of _Saturn_, and
consequently the Distance from Star to Star will not be less than 6000
times the Radius of our _Orbis Magnus_, and consequently upwards of
480,000,000,000 Miles. That this is even less than the real Truth, and
may be defended as a very moderate Computation, grounded upon Reason,
we have infallible Demonstration to witness, and make appear as thus.
[Illustration: Plate XXX.]
We know from the Nature of Distance and Motion that the Stars may
have an annual Parallax, but it is so very small, that the very best
Astronomers have never yet been able to assign what the Quantity really
is. Yet it is allow'd by universal Consent, that it can't possibly be
more that one Minute of a Degree, and may probably be much less. Mr.
_Flamstead_, by repeated Observations, made it in some of them upwards
of 40″; but Mr. _Bradley_ has endeavour'd to prove it is every where
too small to be determined, and assigns this Angle to another Cause.
This way then we cannot make their Distance less; and to prove that
it is something more than I have said it is, let us even increase the
doubtful Parallax of 40″ to the most it possibly can be, _viz._ to
60″ or 1′; and by the Solution of the Triangle, we shall find that
the nearest Star is 6875 times the Radius of the Earth's Orbit from
the Sun: And this tho' more than any other Proportion makes them, is
still undeniably less than the Truth, which every Mathematician will
of course be convinc'd of; and you yourself of force must believe,
when you are told, that the smaller the Angle of Parallax is, the
farther the Body is remov'd from us. By which Rule, according to Mr.
_Flamstead's_ Observations, the Distance must be still greater: By the
optical Experiment of [AT]Mr. _Huygins_, greater still than this; and
according to Mr. _Bradley_, so much more as not even too be determin'd.
[Footnote AT: 27664 Radius's of the _Orbis Magnus_, equal to the
Distance of _Syrius_, whose Parallax should be to answer it but 14″
48‴.]
Now if the rest are in general from each other, allowing the same
Extent of System, and as much to part the like Extreams of active
Virtue, be in such Proportion of aerial Space, it will appear, that to
pass from any one Star to another, we must fly thro' so vast a Tract of
pure Expanse or Ether, that to visit any one of the most neighbouring
Systems, could we travel even as fast as the swiftest Eagle flies, for
Instance, 500 Miles _per_ Day, yet should we be 3,000,000 of Years upon
our way before we could arrive there; and if continuing on to view the
Regions of the rest within the known Creation, Myriads of Ages would be
spent, and yet we could not hope to see the whole of but the smallest
Constellation.
But what Idea of Distance can you receive from this sort of Estimation,
where Numbers arise so very high. I own to you mine are soon quite lost
by this Method of counting, either, Distances or Duration. I believe
few People can range their Ideas with such Perspicuity, as to arrive at
any adequate Notion of any Number above a thousand.
To give you therefore a clearer Idea of Distance, and impress the
Proportions of Space more strongly and fully in your Mind, let us
suppose the Body of the Sun, as I have said before, to be represented
by the Dome of St. _Paul's_; in such Proportion a spherical Body
eighteen Inches Diameter, moving at _Mary-le-bone_, will justly
represent the Earth, and another of five Inches Diameter, describing a
Circle of forty-five Feet and a half Radius round it, will represent
the Orbit and Globe of the Moon. A Body at the _Tower_ of 9,7 Inches,
will represent _Mercury_; and one of 17,9 Inches at St. _James's_
Palace will represent the Planet _Venus_; _Mars_ may be supposed
at a Distance, like that of _Kensington_ or _Greenwich_, 10 Inches
Diameter: _Jupiter_, imagined to be at _Hampton-Court_, or _Dartford_
in _Kent_; and _Saturn_, at _Cliefden_, or near _Chelmsford_: The
first represented by a Globe 15 Foot 4 Inches Diameter, the latter by
one of 11 Feet ¾ Inches and his Ring four Feet broad: These would all
naturally represent the planetary Bodies of our System in their proper
Orbits and proportional Magnitudes, as moving round the Cupola of St.
_Paul's_, as their common Center the Sun. And preserving the same
natural Scale, the Aphelion of the first Comet would be about _Bury_,
the second at _Bristol_, and the third near the City of _Edinburgh_.
But if you will take into your Idea one of the nearest Stars; instead
of the Dome of St. _Paul's_, you must suppose the Sun to be represented
by the gilt Ball upon the Top of it, and then will another such upon
the Top of St. _Peter's_ at _Rome_ represent one of the nearest Stars.
The whole System exhibited in the above Proportion, would be nearly as
follows:
Diameter of the Sun 145 Feet.
_Saturn_ 11,587, his Ring 27,54, its Breadth 4.
_Jupiter_, 15,39.
_Mars_, 10,15 Inches.
the Earth, 18,125.
_Venus_, 17,98
_Mercury_, 9,715
and the Moon, 4,93
[AU]Distance of _Saturn_ from the Sun, 27 Miles, and 1700 Yards.
_Jupiter_, 15 Miles, and 458 Yards.
_Mars_, 4 Miles, and 751 Yards.
the Earth, 2 Miles, and 1632 Yards.
_Venus_, 2 Miles, and 217 Yards.
_Mercury_, 1 Mile, and 267 Yards.
and of the Moon, from us, 45 Yards and a half.
[Footnote AU: Of the Satellites of _Saturn_ in the above Proportion.
The 1} { 27,96}
2} { 35,52} Feet distant from his
3} would be { 50, } Center.
4} {114, }
5} {341,9 }
And those of _Jupiter_.
The 1} { 28,51 }
2} would be { 69,177}
3} {110,224} Feet distant from him.
4} {190, }
]
That of the most distant Comet 390, and the nearest of the Stars not
less than 6875,[AV] Radius's of the _Orbis Magnus_.
[Footnote AV:
° ′ ″
Radius, or Sign of 89 59 30 ---- ---- 10,0000000
Sine substract of 0 0 30 ---- ---- 6,1626961
----------
Hence the Distance 6875,5 ---- ---- 3,8373039
]
Now, if like Creations crowd the vast Depths of Infinity, and if each
are adapted to receive Beings of different Natures, where must our
Wonder and Ideas have end?
As it is evident in the Sign _Taurus_, in _Perseus_, and _Orion_, that
we can plainly perceive Stars to the sixth and ninth Magnitude, the
former with our naked Eye, the other by the Help of Telescopes, the
visional ocular Creation cannot be less than 4,320,000,000,000 Miles in
semi Diameter, and admitting a regular Distribution of those primordial
Bodies amongst themselves, the Depth, or most remote Limits of the
_Vortex Magnus_ from Side to Side, cannot be less than 8 m, m, 640
thousand of Million of Miles, admitting it is no more than what we see;
and lastly, supposing our System to be situated nearly in the Middle of
the _Vortex Magnus_ (which, from the visible Order of the Stars, we may
justly conjecture, with the highest Probability of Truth) the nearest
Distance of the _Ens Primum_, in the Realms of eternal Day, will rise
to 30,000,000,000,000 Miles, but more probably to 100,000,000,000,000
Miles, making the Confines of Creation from Verge to Verge in the first
Case, upwards of 68 Million of Millions of Miles, Diameter, and by the
last above 200′. But, if we compute the Distance of the Stars after the
Manner of _Huygens_, for his Distance of _Syrius_ from the Sun, the
Distance of the Region of Immortality without exceeding Probability may
rise to near 1,000,000,000,000,000 Miles.
Now to pass by any progressive Motion from the outward Verge, or
Borders of the Creation, thro' the starry Regions of Mortality, if I
may call them so, as far as the Center of the _Ens Primum_, or _Sedes
Beatorum_, according to _Homer_, or _Milton's_ Manner of measuring
Space, a Body falling, or a Being moving with a Velocity but of 1000
Feet _per_ Minute, _i. e._ at the Rate of 20,000 Yards _per_ Hour, or
about 300 Miles _per_ Day, would be at least 300,000,000 Years upon
its Journey thither, if not 1,000, m, and perhaps much more, without
offending Probability; but even three Million Centuries, or Ages,
sure is enough to be employ'd, in passing from one Place to another;
therefore, we may conclude, the Soul must have some other Vehicle than
can be found in the Ideas of Matter to convey it so far, at least at
once. Hence we may truly infer, that the Soul must be immaterial, and
that in all Probability there may be States in the Universe so much
more longer lived than ours, that, compared with the Age of Man, the
Age of such Beings may be almost as an Eternity, or rather, as that of
the human Species to that of a Sun-born Insect.
Again, if there are still Stars beyond all these of other Denomination,
which we do not here perceive, how vastly must these Numbers be
increased, to express, almost without Idea, the amazing Whole of this
one visible Creation; but what has been already said, I judge will be
sufficient to show the Immensity of Space, and help you to conceive
the stupendious Nature of an endless Universe; every where the home
Possession, Production, and instantaneous Care, of an infinite good
Being, perfectly wise, and powerful, of whom we can have no Idea more,
than a Being in dark Privation can have of Light, but through the
Lustre of his own resplendent Attributes.
Thus, having attempted to enlarge your Ideas of the Creation in
general, and in some measure having considered the Indefinity of Space,
I shall in the next Place proceed to give you some Account of my
Notions of Time.
As Distance is the Measure of Magnitude and of all Extent, and helps
our Imagination to the Ideas of Space, so are progressive Moments the
Measure of Velocity, and makes us sensible of Duration: And as Space
may be extended through all Infinity, so Time may be continued as to
Eternity. This Succession of temporal Ideas impressed, or excited in
the Mind, as an Effect of Matter in Motion, producing a perpetual
Change, both of Objects earthly and celestial, enables us not only
to reflect upon past Vicissitudes of Nature, but from their regular
Courses, known Order and Returns, predict Phænomena to come, and prove
the periodical Effects of Nature's constant Laws so just and certain,
that Time may be said with Truth, to co-exist with Motion.
Measure being a certain Quantity of Sensation interwove with our Ideas
of Distance and Duration, proceeding from a Reflection of what is
impressed upon the Mind by some external Object, I must again return to
our Mother of Ideas the Earth, and from thence, as I did, of Distance,
frame the original Images best suited to the Understanding, proper for
our Judgment of Duration.
Time takes its first Denomination from the diurnal Rotation of the
Earth upon its Axis, which we call a natural Day, and this for obvious
Reasons we subdivide in twenty-four Parts or Hours. This diurnal
Motion having been successively repeated, and the Day renewed three
hundred and sixty-five Times, we find that all the vegetable World
has gone through all its Variegations, and Nature has again put on
the same Face, adapted to the Season; during which Time, and indeed
which occasions this general Change and Repetition, the Earth is
found to make one intire Revolution round the Sun. This Space, or
Period of Time, we call a solar, or rather a natural Year; and from
our Sensibility of this, and its constituent Parts, both horary and
diurnal, we form our general Judgment of Duration.