John Wesley.

A survey of the wisdom of God in the creation; or, A compendium of natural philosophy .. (Volume 3) online

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near the body of the sun : then they rise far beyond the
,orb of Saturn, ^ome suppose' them to be imperfect
.planets, or such a chaos oi unformed matter, as may
.hereafter be forme J into an earth like outs. Probably
.those rays which they emit, are only vapours, by which

the rays of the sun, are refracted to us.

Hence tiiey have a difterenr appeara.uce, according
,<is tliey are (Jhierenlly situated with regard to the comet:

the nearer they ,are to tlie sun, the more those rays are

increased, and the farther they recede from it, the more
.those are diminished. And hence some imagine that.
,iixd stars, covered with vapours .and .spots, become co



240

mets. It is more probable that comets, like planets, '
have their regular periods : although they frequently es-
rape our observations, as not revolving but in a long
term of years.

They are distinguished from other stars by a large
train of light, which is always opposite to the sun, and
grows fainter and fainter the farther it is from the body
of the comet. When a conret moves from the sun it is
said to be bearded, because that light is seen before it.
When it moves towards the sun, the train follows it,
and is called its tail. When the comet and sun are op-
posite, (the earth being between them) the train is hid
behind the body of the comet, except a little that ap-
pears round it, and is termed its hair.

Sir Isaac Newton has proved, that the heat of the
suu to the comet in December, 1 680, was to his heat
with us at midsummer, as 28000 to one : and that the
heat of the body of the comet was near 2000 times
greater than that of red hot iron.

After having acquired so immense a heat, it must be
a long time in cooling. Sir Isaac computes, that a
globe of red hot iron 200 times as large as the earth,
would scarce be cool in 50,000 years. If then the comet
be supposed to cool a hundred times as fast as red hot
iron, yet since its heat was two thousand times greater,
supposing it of the bigness of the earth, it would not be
cool in a million of years.

Comets seem to be a peculiar kind of planets, which
move in very oblique orbits, and persevere in their mo-
tions, even against the course and direction of the other
planets. Their tails are doubtless vapours emitted by
the comet when heated by the sun. Yet they do not
ascend swiftly fi om it, and then presently disappear ;
but are permanent columns of exhalations, gathered from
* the comet by a gentle motion, and in a great space of
time, which then move with it through the celestial
regions.

One great use of comets probably is, to give moisture



241

to the planets. By their vapours the water spent in
them, may be supplied and recruited. All vegetables
grow from fluids. But when they putrefy, great part of
them turn into dry earth : hence the quantity of dry
earth must continually increase, and the moisture of the
globe decrease. Add to this, that immense quantities of
watry vapours, are continually arrested in the polar
regions, and falling down form mountains of eternal
snow, and rocks of ice that thaw no more. By both
these means the moisture of the planets continually de-
creasing, must in process of time, entirely fail, if it had
not a seasonable supply from some other part of the uni-
verse. Comets therefore are so far from being super-
flous, much more from being blemishes in the universe,
that it may be doubted whether either the animals or ve-
getables of the earth could long subsist without them.

And indeed, if the uses assigned to the comets, by Sir
Isaac Newton be real, as they are not improbable, name-
ly the, supplying the deficiency and expenses of all sorts
of fluids necessary to the earth : I mean not only light
and heat to the sun, and watry vapours to our atmos-
phere, but the most subtle, most useful, and necessary
part (towards life and vegetation) to the air ; then
these wandering, frightful bodies, may be justly con-
ceived joining in. the chorus, arid loudly resounding the
common hallelujah.

But the astronomy of comets, says Mr. Brydon is
clogged with very great difficulties, ,and even some
seeming absurdities. It is difficult to conceive, that
these immense bodies, after being drawn to the sun,
with the velocity of a million of miles in an hour, when
they have at last come almost to touch him, should
then fly off from his body, with the same velocity they
approached it, and that too, by the power of this very
motion, that his attraction has occasioned. The demon-
stration of this, I remember is very curious and ingeni-
ous* but 1 wish it may be entirely free from sophistry.
No doubt, in bodies moving in curves round a fixed cen-
tre, as the centripetal motion Increases, the centrifugal



MS

increases likewise : but .how this motion, v
only generated by tlie former, should at last get the bet-
ter of the power that produces it, and. that too, ;*l tbr
very time this power has acquired its utmost force and
energy, seems somewhat difficult to conceive. It is the
only instance I know, wherein the effect increasing re-
gularly with the cause; at last, whilst the cause is still
acting with full vigour, the eiiect entirely gets the better
of the cause, and leaves it in the lurch. For the body
attracted, is at last carried away with infinite velocity
ffom the attracting body. By what powtr is it carried
away? 'Why, say our philosophers, by the very power
of this attraction, which has now produced a new power
superior to itself : to wit, the Centrifugal force. How-
ever, perhaps all this inay.be reconcileable to reason ; far
be it from me to presume to attack so glorious a system
as that of attraction. The law that the heavenly bodies
are said to observe, in describing equal areas in equal
times, is supposed to be demonstrated, and by this it
would uppear,' that the centripetal and centrifugal forces
alternately get the mastery of one another.

However, I cannot help thinking it somewhat hard to
conceive, that gravity should always get the better of the
centrifugal force, at the very time that its action is the
smallest, when the comet is at the greatest distance from
the sun ; and that the centrifugal force should get the
better of gravity, at the very time that its action is the
greatest, when the comet is at its nearest point to the sun.

To a common observer it would rather appear, that
the sun, like an electric body, after it had once charged
tlie objects that it attracted, with its own efrluvia or at-
mosphere, by degrees loses its attraction, and at last
even repels them, and that the attracting power, like
what we likewise observe in electricity ,> does not return
again till the effluvia imbibed from the attracting body
are dispelled or dissipated; when it is a^ain attracted
and soon alternately. For it appears (at least to an un
philosophical observer^ somewhat repugnant to reason
to &ay, that a body ih ing oft irom another body some
thousands of miles in a minute, should all the while be



243

violently attracted by that body : and that it it is cvea
by virtue of this very attraction that it is flying off from
it. He would probably ask, what more it could do f
pray, were it really to be repelled 1

Had the system of electricity, and of repulsion, as
well as attraction, been known and established in the
last age, doubtless the profound genius of Newton would
have called it to his aid, and perhaps accounted in a
more satisfactory manner for many of the great pheno-
mena of the heavens.

To the best of my remembrance, we know of ne body
that possesses, in any considerable degree, the power of
attraction, that in certain circumstances does not likewise
possess the power of repulsion : the magnet, the tour-
malin, amber, glass, and every electrical substance.
Now, from analogy, as we find the sun so powerfully'
endowed with attraction, wby may we not likewise
suppose him to be possessed of repulsion? Indeed,
this very power seems to be confessed by the Newtoni-
ans, to reside in the sun in a most wonderful degree ;
for they assure us, he repels the rays or light with such
amazing force, that they fly upwards of 80 millions of
miles in seven minutes. Now why should we confine
this repulsion to the rays of light only ? As they are
material, may not other matter brought near his body*
be aiiected in the same manner 7 Indeed one would
imagine, that their motion alone would create the most
violent repulsion ; and that the force with which they
are perpetually flowing from the sun, would most effec-
TUcilU prevent every other body from approaching him ;
foi um we tiud is the constant effect of a rapid stream
of any other nature. But let us examine a liUle more
his effects upt)n comets. The tails of these bodies are
probably their atmospheres, rendered highly electrical,
either from the violence of their motion, or from their
proxi?-:iiy to the sun. Of all the bodies v*e knov\, there
is none in so constant ami so vioi'-nt an electrical state,
as the higher regions of our own atmosphere. Of this
1 have long been convinced ; for send up a kite with a

VOL. III. . 'M



244

viall^wire about its string, only to the height of twelve
or thirteen hundred feet, and at ati times it will pro-
duce fire, as I have found by frequent experience ; some-
times when the air was perfectly clear, without a cloud
in the hemisphere ; at other times, when it was thick and
hazy, and totally unfit for electrical operations below.
Now as this is the case at so small a height, and as we
find the effect still grows stronger in proportion as the
kite advances (for I have sometimes observed, that a
little blast of wind, suddenly raising it about a hundred
feet, has more than doubled the effect) what must it be
hi very great elevations? Indeed we may often judge of
it from the violence with which the clouds are agitated,
from the meteors formed above the region of the cjouds,
and particularly from the Aurora Borealis, which has
been ob erved to have much the same colour and appear-
ance as the matter that forms the tails of comets.

There is a species of comets, says the same gentleman,
that have not tails : these are certainly bodies of a very
different nature from those with tails, to which indeed
they appear even to bear a much less resemblance thsui
they do to planets : and it is no small proof of the little
progress \ve have made in the knowledge of the universe
that they have not as yet been distinguished by a diifer-
ent name.

This is the third kind of body that has been discover-
ed in our system, that all appear essentially different
from each other, that are probably regulated by differ-
ent laws, and intended for very different purposes. How
much will posterity, be astonished at our ignorance, and
wonder that this system should have existed for so
many thousand years, before we were in the least ac-
quainted with one half of it, or had even invented names
to distinguish its different members.

I have no doubt, that in future ages the number of
the comets, the form of their orbits, and time of their
revolutions, will be as clearly demonstrated, as that of
the -p-.-n K>ts. It is our cQuntrynian Dr. HalJey, who has



begun tin's 12 re at work, which may be considered
now as in its earliest infancy. These bodies, ioo,
thick atmospheres, but without tails,
their proper places aseeftauierf, and will 1*0 '
eonfouirded with bodies to which they bear no it .
blance or connection.

Comets with tails have seldom been visible,' but OH
their recess from the sun. It is he that kh'dlos them
up, and gives them that alarming appearance in the hea-
vens. On the contrary, those without tails, have seldom,
perhaps never, been observed but on their ap;
him. I do not recollect any whose return ha
lerably well ascertained, 'I remember,- indeed, a lev/
years ago,* a small jone, that was said io have been dis-
covered by a telescope, after it had passed the sun, but
never more became visible to the naked C 4 >e. This as-
sertion is easily made, and nobody can contradict ;. but
it does not at all appear probable, that it should have
been so much less luminous after it had passed ihe sun,
than before it approached him ; and I will own, when
I have heard that the return of these comets had escaped
the eyes of the most acute astronomers, ,1 have been
tempted to think that they did not return at all, but vvr,r^
absorbed in the body of the sun, which their violent
motion toward him seemed to indicate. Indeed, I have
often wished that this discovery might be made, as it
would in some measure account for What has as yol-"bcen
looked upon as unaccountable; that the sun, notwith-
standing his daily waste from enlightening the universe,
never appears diminished either in .size or light. Surely
this waste must be h.- ueiise,and were there not in nature
some hidden provision for supplying it, in the space of
six thousand years, (supposing the world to be no older)
the planets must have got to a much greater .distance
from his body, by the vast dimuuition of his attraction :
they must likewise have moved much slower, and conse-
quently the length of ourjear must have been increased.
Nothiug of all this seems to be the case : he neither ap-
pears diminished, nor our distance from him increased ;
hJb light, heat, and attraction seem to be the same as
M 2



246

ever; and the motion of the planets round him is per-
formed in the same time ; of consequence, his quantity of
matter still continues the same. How then is this vast
waste supplied ? May there not be millions of bodies
attracted by him from the boundless regions of space,
that are never perceived by us 1 Comets on their road
to him, have several times been accidentally discovered
by telescopes that were never seen by the naked eye.
Indeed the number of black spots on the sun,/ seems to
indicate, that there is always a quantity of matter there
only in preparation to give light, but not yet refined and
pure enough to throw off rays like the rest of his body.
For I think we can hardly conceive, that any matter
can remain long on the body of the sun without be-
coming luminous ; and so we find these spots often disap-
pear ; that is to say, the matter of which they are com-
posed is then perfectly melted, and has acquired the
same degree of heat and light as the rest of his body.
Even in glass houses, and other very hot furnaces, most
sorts of matter very soon acquire the same colour and
appearance as the fire, and emit rays of light like it.
But how much more must this be the case at the surface
of the sun ? When Newton computes, that even at
many thousand miles distant from it> a bedy would ac-
quire a degree of heat two thousand times greater than
that of red-hot iron. It has generally been understood,
that he said the great comet really did acquire this degree
of heat : but this is certainly a mistake : Sir Isaac's ex-
pression, to the best of my remembrance, is, that it might
.have acquired it. And if we consider the very great
size of that body, and the short time of its perihelion, the
thing will appear impossible ; nor indeed do I think we
can conceive" that a body only as large as our earth,
(and the spots on tlie sun are often much larger), could
be reduced to fusion even on his surface, but after a con-
siderable space of time.

Now it seems to be universally supposed, that the
rays of light are really particles of matter, proceeding
from the bodv of the sun. If so it is absolutely necessary
that we should fall upon some such method of sending



S47

him back a supply of those rays, otherwise let his stock
fee ever so great, it must be exhausted.

10. It is commonly supposed that the fixed stars are
so many suns, shining with their own light : arid that
each of them has a set of planets moving round Jt : as
the earth, and the other planets do round our sun. It
may be so, or it may not ; for we know nothing about
them : nor is it possible we should know more. For
even when viewed with the best telescopes, they appear
no larger than they do to the naked eye. They are di-
vided, according to their size, into stars of the first, se-
cond, and so on to the sixth magnitude.

Even a good eye seldom sees more than a hundred
stars at a time, in the clearest heaven. The appearance*
of vast numbers in winter nights, is a mere deception of
our sight, occasioned by our viewing them confusedly,
not in any regular order.

Yet are they really almost infinite. For a good tele-
scope directed to almost any part of the heavens, dis-
covers numbers unseen by the naked eye, particularly in.
the milky way : which is indeed nothing else but an as-
semblage of stars, too remote to be seen singly, btit so
close to each other, as to give that brightness to so large
a part of the heavens.

There are six or seven of these nebulous stars, as they
are called. They are indeed compound stars, consisting
of multitudes of single ones. In some of these appears
a bright lucid part, in which some stars appear, as from
a white cloud, and these are reckoned to be regions
of a peculiar nature, enjoying an uninterrupted, ever-
lasting day.

The seven stars so called, probably were seven once ;
but one of them became extinct, even before the time of
Augustus Cxsar : and no more than six have appeared
ever since. But these, likewise, when viewed tlnough a
good telescope, are more than can easily be numbered.

A hundred and twenty-five years before Christ, Hip-

M 3



248

parries discovered anew star. In 1572 TychoBrahe
observed another Its magnitude Jit first exceeded the
biggest of our stars. It equalled that of Venus when
nearest the earth, ;ind was seen in fair day light. It
Continued sixteen months, toward the end of which it
grew less till it totally disappeared. We have an ac-
count of one appearing at least thrice before, at the in-
terval of 150 yt-ars. Probably it was the same star, and
uill return at the staled time.

Many other new stars have beeil observed in this cen-
tnry to appear and disappear; and it is certain from the
c(u catalogues, that many of the ancient stars are not
now visible.

There are now wanting two stars of the second mag-
nitude in the ship Argo, which were seen till the year
16 4. But there was not the least sign of them in
It Co. Accurate astronomers have observed many more
such changes in the fixed stars, to the number of a
hundred.

Are these temporary stars a sort of planets 1 Are they
fixed stars, .v/hich being covered with spols'like those
"observed on the sun, lose their brightness, and con^e-
queniSy disappear ? Or are they comets, which take so
vast a time to perform their revolutions, as seldom to
have their returns perceived ?

11. It remains only to make some improvement of
what has been observed, concerning the system of the
universe. And first, we may observe the due situation
of the heavenly bodies. 1. None of them interfere
Tvkh each other. Had the universe been the work of
any but the wise architect, there would have been many
inconveniences in 'the situation of such a prodigious num-
ber of immense globes* Some would have been too
lie's r or too far off; some would have incommoded
others. But instead of this, all the globes which fall
under our notice, are set at such a due distance, as not



249

only to avoid all violent concourse, but'' not to shade
each other, so as to hinder each others kindly- influence
or to occasion noxious ones. 2- As it is one great in-
stance of the skill of an architect, to give due proportion
to lii.s works, so this abundantly appears in all the hea-
venly bodies that come under our cognizance. Curious
order, and due and nice proportions are observed in their
situations. The sun is placed in the centre of his system,
to give all his planets heat and light. Then follow the
several planets surrounding him, not scattered at all ad-
ventures, but at due distances from the sun, as well as
from one another. And this is discernible, not only in
the primary, but the secondary planets too : in the five
moons that attend Saturn, and the four that accompany
Jupiter.

The wisdom of the Creator appears secondly, from
the motions of the heavens and the earth. That these
vast globes should move at all, proves seine being that
has power to put them in motion : seeing matter cannot
move itself. And suppose them moved by the sun,
the ether, or some oilier primary mover, still we must
recur to some first cause who was able to put the mover
into motion. And this could be no other than the hand
of the Almighty. What farther shews both his power
and wisdom, is, that those motions are not at random,
or in inconvenient lines and orbs, but such as manifest
the deepest counsel. That every planet should have as
many and various motions, as the world and its inhabi-
tants have occasion for, must be the work of a wise and
kind, as well as an omnipotent creator.

In particular, the diurnal motion of these globes
she\ys the wisdom of the Creator. Of what prodigious
use is this ? Were the planets always to stand still, half
of each globe would be dazzled and parched with un-
ceasing day, and the other half wrapt in everlasting dark-
ness. Were this the case with our globe, a great part of
it at least would scarce be habitable. It would neither
agree with the state of man or other animals, nor of ve-
M 4



250

getables. How could the vapours be raised to supply
the earth with cooling clouds and fruitful showers ?
How could the winds be excited to fan the atmosphere
with their pleasant and healthful gales ? How could ve-
getables be raised up by the kindly heat of the day, and
tempered by the dews and cool of the night] How could
men and other animals gather their food, and perform
the various labours of the day, and then under the sa-
lutary influences of the night, recruit themselves with
rest and sleep

And as the diurnal, so the annual motion of the hea-
venly bodies, is a clear manifestation of the Creator's
\visdom : especially when \ve consider the different paths
of their diurnal and annual motions. These lie not in a
very different plane, nor in the same, but a little crossing
one another : the diurnal lying in or parrallel, to the
equator, the annual, at an inclination of twenty-three
degrees and a half. A glorious contrivance thi> for the
good of our globe, and tor all the rest that have the
same annual motion. For were the earth's annual mo-
tion to be always in the same plane with the diurnal,
we might indeed be sometimes nearer to the sun than
we now -are. But we should miss of those kindly in-
creases of day and night, which the approach f earth to
one or the other pole occasions. This is likewise the
great cause of summer and winter. Indeed one cause of
them is, the longer or shorter continuance of the sun
above the horizon. As it continues longer in summer,
it increases the heat, as much as-it lengthens the day :
and just the contrary in winter. But the chief cause is,
the oblique or perpendicular direction of the sun's rays.
For 1. Perpendicular rays strike on any plane, with
greater force than oblique. And 2. A greater number
of rays fall within the same compass, in a perpendicular
than in an oblique direction.

A, farther manifestation of the Creator's wisdom we
have in the perpetuity, constancy, and regularity of those
motions, flow, without an Almighty Guide, should



251

those vast bodies continue their courses throughout
all ages ? How should they perform their usual stages,
without the least intermission or disorder! What a piece
of clock-work under heaven, was ever comparable to
this ? How steadily do all these motions conspire, ' to
answer the ends of divine providence, to dispatch the
noble offices of the several globes, to comfort and cherish
every thing residing on them, by the useful change
of day and night, and the several seasons of the year.

We may learn Ihe wisdom of God, thirdly, from the
figure of the heavenly bodies, so well suited to the
motions, and to the whole state and convenience of them.
And 1 . They are all nearly spherical : I say, nearly, to
allow for their difference between their polar and equa-
torial diameter. Now this figure is both more capa-
cious than any other, and more agreeable to a mass in
motion, each part of it being at a due distance from the
centre of motion and gravity : besides, without this
there could have been no such agreeable alterations of
day and night, of heat and cold. And as to our own
globe, the winds could not have fanned the air, as now,
but must have been greatly retarded, if not wholly stopt,
by the angles and jettings out of other figures. Lastly,


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Online LibraryJohn WesleyA survey of the wisdom of God in the creation; or, A compendium of natural philosophy .. (Volume 3) → online text (page 21 of 24)