Symmes's Theory of Concentric Spheres / Demonstrating that the Earth is hollow, habitable within, and widely open about the poles

by James McBride; John Cleves Symmes

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?