_Symmes's Theory supported by arguments drawn from the principles
inherent in matter, and the consequences resulting from motion;
tending to show that, from necessity, matter must form itself into
concentric circles or spheres, such as Symmes describes the earth to
be composed of._
It is a principle laid down by Sir Isaac Newton, the correctness of
which is generally admitted, that "matter attracts matter in proportion
to its quantity and the squares of its distances inversely." Captain
Symmes contends that gravity consists in a certain expansive quality
in the molecules which constitute the aerial fluid called æther,
which fills universal space, and creates a pushing, instead of a
pulling power. However, let either be correct, I conceive it cannot
materially affect the principles necessary to constitute concentric
spheres: either principle, I apprehend, would lead us nearly to the
same results. When matter was in chaos, or in a form not solid,
promiscuously disseminated through universal space, suppose it then
should at once receive the impression of those universal laws by which
it is governed, and see what would be the consequence.
According to Sir Isaac Newton's principles of gravity, the particle
of matter that happened to be the largest would attract the smaller
in its neighbourhood, which would increase the power of attraction in
proportion to the increase of matter, until all in the universe would
be collected into one vast body in the centre of space, and there
remain motionless and at rest forever. This, however, we find not to be
the case; for innumerable bodies of matter, differing in magnitude, are
known to exist throughout the universe, arranged at suitable distances
from each other, and performing certain revolutions in obedience to
certain fixed laws impressed on them.
Now suppose all the matter in our globe to be an extended liquid mass,
the particles so disengaged from each other, as to take their positions
according to the _established_ laws of matter, and then see what would
be the consequences resulting from motion and gravity. Taking the
laws of Newton for our guide, the particles of matter in the centre
would be operated on by the power of gravity equally on all sides and
consequently be stationary. Suppose then a line struck through this
globe of matter, so as to make a globe of half the diameter of the
whole in the centre, it is plain that the inner globe would not contain
more than one eighth part as much matter as the surrounding one; hence
it would be attracted towards the surface more than to the centre, were
it not for the attraction of the matter on the opposite side exerting
an influence upon it――but this being removed to so much greater
distance, would not be more than an equipoise to the other.
The diameter of our globe, according to the best observation, is
believed to be about 7970 English miles, and its circumference 25,038:
consequently, if it were solid, it would contain 265,078,559,622 cubic
miles of matter; while a globe of only half the diameter, would
contain only 33,134,819,952.[3]
Suppose our globe divided into parts of one square mile on the surface,
bounded by straight lines converging to a point at the centre, as the
subjoined figure represents:
[Illustration]
and then suppose there were no other particles of matter in the
universe but A and B, A containing 1,328 cubic miles of matter, and B
only 166, A would attract B so as to make their centre of attraction at
O, which point would become at once the common centre: but admitting
the whole matter of the globe to exist, A would still exert its
influence on B, but both would be operated upon by T and S and the
surrounding matter, all perhaps, tending to one common centre. However,
I imagine that the tending to the centre would not be so great as is
contended for by the generally received theory, which alleges that
matter at the centre of the earth is four times as hard as hammered
iron. The Newtonian philosophy appears to contemplate a globe at rest,
and not in such rapid motion as we know the earth and other planetary
bodies to be in, communicating to them a centrifugal force, which tends
to throw matter from the centre. The rotary motion of each planet is no
doubt regulated by the quantity of matter it contains: so that at its
surface centrifugal and centripetal forces are equally balanced――the
rotary motion being adequate to communicate a force to counter-balance
the force of gravity.
Newton ascertained by his investigations of the properties and
principles of matter, the earth to be a globe flattened at the poles:
and the French philosophers afterwards confirmed this fact by measuring
a degree in different latitudes. This difference between the equatorial
and polar diameters of the earth, and of the other planets which are
also known to be of that shape, is ascribed by those philosophers who
attempt to account for such a formation, to the projectile force of the
globe at the equator occasioned by its rotary motion. This is admitting
that the matter of our globe was once in so soft a state as to take its
form from motion; for were the earth a compact solid body, and four
times as hard as hammered iron at the centre, (as the Newtonian system
alleges) this rotary motion round an imaginary axis could never give
to the globe the form of an oblate spheroid, as is ascertained to be
the fact; because a hard solid body moving in empty space, could not be
supposed to yield into that shape by any law of action as yet unfolded
by science.
But were the matter of this globe thrown into a confused, disorganized
state, and then put into a quick rotary motion, such as it is known to
have, it would throw off from the centre towards the surface, first the
heaviest, and next the lighter substances, which is the very order in
which they are found to be arranged, in the composition of the earth.
This principle, for it is simply the principle of projectile force,
will account for mountains, hills, vallies, plains; and for nearly all
the inequalities on the face of the earth. These circumstances depend
on the density of substances composing the earth. Substances of the
greatest specific gravity are susceptible of the greatest projectile
force; and hence we find that mountains are composed of heavy masses
of rock, mineral substances, and heavy earths; hills, or the next
highest eminences, of earth of the next specific gravity; and plains,
or level lands, of lighter substances. Had the earth originally been
composed of one uniform substance, sand, for example, of equal fineness
and weight, the whole surface of the globe would have presented one
uniform level or unbroken plain. But, presuming that it was originally
composed of, at least, earths of different densities, the heaviest
masses would be first thrown out and raise their heads above the
surface of the ocean: thus islands would be formed; and clusters of
islands would form continents, rearing their lofty heads into the air;
and, if the substances of which they were originally composed, were not
as hard as the rocks which we now find on them, the sun and changing
temperature of the climates, might convert certain kinds of earth into
masses of stone, increasing in specific gravity by petrifaction, and
other causes, until the towering peaks of the Alps and Andes assumed
their present solid form. One continent having thus emerged, another
would naturally be produced simultaneously on the opposite side of the
sphere, as an equipoise to the first, to keep equal the earth's motion;
until all the heavy substances should be thrown out and united in a
compact sphere.
To an observer of the earth the crust every where appears to indicate
the emergence of land from water: almost the whole surface of the
solid crust is alluvial, and by reasoning and reflecting, we are led
to the conclusion, that the solid parts of our globe are nothing more
than a crust, and formed into concentric spheres, in accordance with
the principles of projectile force. I would ask, what proofs have we,
that the sphere we inhabit is solid beyond the degree of thickness
necessary to preserve it from injury by its rapid motion round the sun,
by its diurnal motion round its own axis, and by its motion round its
common centre of gravity with the moon? It has been ascertained with
mathematical certainty, that the large planet Jupiter, is more than
1300 times the bulk of the earth, and Saturn independent of his double
ring, is about 1000 times the size. If we apply to those prodigious
bodies, the reasoning of Newton relative to plastic forms moving
variously, there is no just grounds for concluding that they are solid
substances to their centres. If they were, their vast weight and remote
position would require much more attraction than probably even the sun
could furnish, to keep them within their orbits.
The acknowledged and received laws of gravity, together with the
measurements made on the same meridian, in different latitudes, have
demonstrated to us that the greatest mathematicians have been mistaken
as to the real figure of the earth. It is for schoolmen to make exact
calculations, respecting the force of gravity, and centrifugal and
centripetal forces; it is for them to determine with mathematical
certainty where matter, left to its own laws, would settle; for such
undertakings, I acknowledge my incompetency. But I have long had strong
doubts, whether the laws of gravity are well understood; or whether the
rules on which these calculations could be accurately made, are exactly
known. However, I take the broad principles of nature, as presented to
my view, for my guide; and draw my conclusions from what I have seen or
what is well known to exist.
Observe the boy hurling a stone from a sling; he whirls it round his
head for a minute to acquire a certain degree of centrifugal force,
and although it is not whirled with half the velocity the earth
revolves on its axis, yet as soon as it is released from confinement,
notwithstanding the whole power of the earth is operating on it with
all the force of gravity, the centrifugal force which the stone
acquired by the whirling is sufficient to carry it off, at a tangent to
the circle described by the sling, for a very considerable distance,
before the gravity of the earth and atmospheric obstruction can force
it to the ground.
If you will take the trouble to examine a mechanic grinding cutlery
on a large stone that is smooth on the sides and has a quick motion,
you may observe that if a certain portion of water be poured on the
perpendicular side whilst the stone is turning, it does not settle or
form itself into a body round the crank or axis; nor does the gravity
of the earth draw it from the surface, but forms itself on the side
of the stone into something resembling concentric circles, one within
another. The surface of the earth, I apprehend, revolves with much
greater velocity than any grindstone; and the substances composing the
spheres are much firmer than water.
Most of us, I presume, have seen persons for amusement, in displaying
feats of dexterity, place a full glass of wine or water on a hoop, and
whirl it round their heads without spilling one drop. The centrifugal
force it acquires by the revolutions overcomes the power of gravity,
although nothing appears to support it but the common atmosphere.
Another experiment, producing a similar effect, might be made with
a cup filled with fine sand. On the surface of the sand, describe a
circle nearly in the centre; it will then be apparent, on observing
the cup, that the sand within the circle, provided the particles
attract one another as the planets do, is as much attracted towards one
verge of the cup as the other; owing to its being equally surrounded
by matter or sand, and therefore it can be but very little, if any,
gravitated centrewise. Hence, being in a degree suspended, only a
small horizontal rotary motion is required to whirl it towards the
rim or sides of the cup into a circular form; and hence it follows,
that those particles of sand lying equidistant from the inner side
of the circle of sand thus formed, and the outer side would be in
like manner balanced, or supported, by being equally gravitated in
both directions. A disposition would thus be produced to form into
concentric circles, and it would therefore follow, that successive
similar dispositions to subdivision should occur, gradually lessening
in force and quantity. This principle applied to the earth or other
planets, would cause them to be formed into concentric spheres; and
would throw the matter from the axis, as well at the poles, as at the
centre, and thereby constitute open poles.
Another simple experiment might also be made, to illustrate that a
disposition to concentric spheres does exist in nature. On a piece
of paper sift a small quantity of very fine magnetic particles, such
as steel or iron filings, under which hold a loadstone; and you will
observe that the attractive power of the magnet will cause the filings
on the paper to arrange themselves into various concentric circles,
nearly regular and equidistant from each other. From what cause should
this take place, rather than that the filings should be accumulated
into one mass?
Various have been the conjectures relative to the cause and origin of
the meteoric stones, or fire balls, which have been known to fall to
the earth, in all ages, and in various parts of the world. Some have
imagined them to be precipitated from a comet or some of the planets;
others that they come from the moon; and Captain Symmes's opinion,
I believe, is that they are formed isolated in space by spontaneous
accumulations, as by attracting molecules of matter at first in a
fluid state, which afterwards solidifies by heat or motion. But come
from whence they may, they are said to be constituted of a substance
unknown to our geologists; and in several instances the fragments have
been ascertained to consist of pieces, some of which have concave and
some convex surfaces, affording a certain proof that previous to their
descent, they had been constituted of hollow spheres.
Professor Silliman, of Yale college, has preserved some of the
fragments of one of these fire balls; and in his valuable journal,
has given the public an able description of the facts which occurred,
when they fell. This fire ball fell in the state of Connecticut, in
the year 1807, producing three distinct reports, like a cannon, making
three convulsive leaps or throes in its course, which were simultaneous
no doubt with the explosions, becoming less luminous after each, and
being quite extinguished at the third. Three showers of stones fell
to the earth in a line with its course; the second shower fell five
miles distant from the first, and the last three or four miles from the
second. Some of the fragments were found to be concave, others convex,
and especially on those sides of the fragments which were glazed with
sooty crusted surface, as if vitrified.
These phenomena are precisely such as would occur, supposing the fire
ball to have been a small satellite, or erratic planet, at first fluid,
which had become so condensed by the increased action of terrestrial
gravity, occasioned by its sudden approach, as to cause its fluid parts
to chrystalize and form into, at least, three concentric spheres; and
the latent heat and light set free by such rapid condensation as to
produce the meteoric flame; which in this case was almost equal in
light to that of the sun at mid-day. As soon as the spheres became
sufficiently solidified to prevent the heated aerial fluid, contained
in the mid-plane cavities of the spheres, from passing out with
freedom, when expanded by the heat; or let the atmospheric air pass
in, in case a condensation within afforded a vacuum; the solid crusts
of the spheres would be disruptured successively one after the other;
lose their regular rotation, and fall in fragments to the earth. The
fall of this body is not a solitary instance of the kind: others have
fallen in many parts of the earth, attended with phenomena more or less
the same.
On the 16th of January, 1818, in Florida, near Mobile bay, a fire ball
bursted with a considerable report. Immediately before the explosion,
it was observed to project a cone of fire from each pole horizontally
and at right angles with its course. Its bursting like a bomb-shell,
indicated that it must have been hollow; and the two cones of light
which appeared, beside its train, showed that it was open at the poles.
Turn your attention to the general economy of nature throughout
her works, and you will perceive in various and almost innumerable
substances that she forms hollow cylinders or spheres in the room of
solid ones. Enquire of the botanist, and he will tell you that the
plants which spring up spontaneously, agreeable to the established
laws of nature, are hollow cylinders. If a hollow globe would answer
the ends of supporting organic life as well as a solid one――why not
be hollow, as well as a stalk of wheat? or by what laws is the stalk
of wheat governed, that it should _always_ grow hollow? What law in
nature causes the quills and feathers of a bird to be hollow cylinders?
Why are they not solid? I presume it is for this plain reason, that
nature, throughout all her works, has wisely assigned to every thing
just matter enough for strength and usefulness; and has in no case
overburthened it with unnecessary and cumbrous weight.
Enquire of the anatomist, and he will tell you that the large bones
of all animals are hollow, and particularly that the bones of birds
are more than ordinarily so: even the minutest hairs of our heads are
hollow.
Go to the mineralist, and he will inform you that the stone called
Ærolites, and many other mineral bodies, are composed of hollow
concentric circles; and, that strata of different kinds abound in
various mineral substances. Even the earth itself is composed,
as geologists tell us, of various strata, composed of different
substances, and varying from one degree of density to another. If
every part of our globe be regulated according to the received laws of
gravity, and the relative density of matter, why do we find almost all
over the world, light alluvial soil in the vallies and plains; and on
the tops of the highest mountains, the more heavy granite, and some of
the heaviest substances that nature knows? We can hardly indulge the
thought that all this is the work of volcanic eruptions or some dread
throe of nature.
However, if we direct our attention alone to those general laws which
are known, and which are believed to govern matter, I apprehend it
would be very difficult to account for the creation of worlds, and
the admirable arrangement which subsists throughout the universe. To
account for every thing, either according to the old or new theory,
would be attempting too much. It would be placing the Deity in some
corner of the universe an idle spectator, whilst matter governed by its
own laws, was forming itself into worlds and systems; the bare thought
of which is irreverent. Is the existence of matter owing to some other
first cause, or did matter create itself, and impress upon itself the
laws which govern it? Such an idea is absurd. We might as well imagine
that matter created God, as itself. By attempting to trace every effect
to some natural cause, is attempting to do more than we shall ever be
able to accomplish. Such a course of reasoning must lead us to the
conclusion that there is no God, or first cause; or, at least, to what
would be nearly the same thing, that there is no need of one.
But in reasoning upon this subject, I take it for granted, that there
is a God, and that he is the first cause of all things, the creator of
all the orbs in the universe, be they either solid globes or concentric
spheres; and I hope such is the reader's belief. And I cannot discover
in this any thing derogatory from His infinite power, wisdom, or divine
economy, in the formation of a hollow world and concentric spheres, any
more than in that of solid ones. I should rather be of opinion, that
a construction of all the orbs in creation, on a plan corresponding
with Symmes's theory, would display the highest possible degree of
perfection, wisdom, and goodness――the most perfect system of creative
economy――and, (as Dr. Mitchill expresses it) _a great saving of stuff_.
FOOTNOTE:
[3] The solidity of the earth is easily calculated by the measure of a
meridional degree; but the result will be different according to the
measurement assumed, as the length of a degree differs in different
latitudes. "Notwithstanding all the admeasurements that have hitherto
been made, it has never been demonstrated, in a satisfactory manner,
that the earth is strictly a spheroid; indeed, from observations made
in different parts of the earth, it appears that its figure is by no
means that of a regular spheroid, nor that of any other known regular
mathematical figure; and the only certain conclusions that can be drawn
from the works of the several gentlemen employed to measure the earth
is, that the earth is something more flat at the poles than at the
equator." [Keith on globes p. 56. New-York, 1811.]
According to Mott's translation of Newton's Principia, book 3, page
243, the equatorial diameter of the earth is 7964 English miles, and
the polar diameter 7929, for as 230:229::7964:7929 miles, the polar
axis.
Cassini, who adopted Picard's measure of a degree, makes the diameter
of the earth 7967 statute miles; others have estimated it at 7917,
and some at 7910 miles. But the estimate which is now esteemed most
correct, I believe, is, that the equatorial diameter is 7977 English
miles, and the polar diameter 7940. From this we may ascertain the
solid contents of the earth. The axis of the earth then assumed to be
7940 and 7977 miles respectively, the area of the generating eclipse is
(7940 × 7977 × 0,7854=) 49745178,252: and its area multiplied by two
thirds of the longer axis, gives the solidity equal to (49745178,252 ×
2/3 × 7977=) 264544857944,136 cubic miles.