Outlines of a mechanical theory of storms

by Thomas Bassnett

DIFFICULTIES OF THIS VIEW.

This, then, is the state of the case: Matter attracts matter directly as the mass, and inversely as the squares of the distances. This law is derived from the planetary motions; space is, consequently, a void; and, therefore, the power which gives mechanical momentum to matter, is transferred from one end of creation to the other, without any physical medium to convey the impulse. At the present day the doctrines of Descartes are considered absurd; yet here is an absurdity of a far deeper dye, without we resort to the miraculous, which at once obliterates the connection between cause and effect, which it is the peculiar province of physical science to develop. Let us take another view. The present doctrine of light teaches that light is an undulation of an elastic medium necessarily filling all space; and this branch of science probably rests on higher and surer grounds than any other. Every test applied to it by the refinements of modern skill, strengthens its claims. Here then the Newtonian vacuum is no longer a void. If we get over this difficulty, by attributing to this medium a degree of tenuity almost spiritual, we shall run upon Scylla while endeavoring to shun Charybdis. Light and heat come bound together from the sun, by the same path, and with the same velocity. Heat is therefore due also to an excitement of this attenuated medium. Yet this heat puts our atmosphere in motion, impels onward the waves of the sea, wafts our ships to distant climes, grinds our corn, and in various ways does the work of man. If we expose a mass of metal to the sun’s rays for a single hour the temperature will be raised. To do the same by an artificial fire, would consume fuel, and this fuel would generate the strength or force of a horse. Estimate, therefore, the amount of force received from the sun in a single day for the whole globe, and we shall find that nothing but a material medium will suffice to convey this force.

Let us appeal to analogy. The undulations of our atmosphere produce sound; that is, convey to the ear a part of a mechanical force imparted to a solid body—a bell for instance. Let us suppose this force to equal one pound. On account of the elasticity of the bell, the whole of the force is not instantaneously imparted to the surrounding air; but the denser the air the sooner it loses its motion. In a dense fluid like water, the motion is imparted quickly, and the sound is not a ring but a click. If we diminish the density of the air, the loss of motion is retarded; so that we might conceive it possible, provided the bell could be suspended in a perfect vacuum, without a mechanical tie, and there was no friction to overcome from the rigidity of its particles, that the bell would vibrate forever, although its sound could never reach the ear. We see, therefore, that the mechanical effect in a given time, is owing to the density of the medium. But can we resort to such an analogy? Every discovery in the science confirms more and more the analogy between the motions of air and the medium of space; the angle of reflexion and incidence follows the same law in both; the law of radiation and interference; and if experiments were instituted, there can be but little doubt that sound has also got its spectrum.

ETHER IMPONDERABLE.

The medium of space, therefore, is capable of conveying a mechanical force from one body to another; it therefore possesses inertia. Does it also possess gravity? If we forsake not the principles of science, it is but right that we expect science shall abide by her own principles. Condensation in every elastic medium is as the compressing power, according to all experiments. In the case of our atmosphere under the law of gravitation, the density of air, (supposing it to be infinitely expansible,) at a height only of ten semidiameters of the earth above its surface, would have only a density equal to the density of one cubic inch of such air we breathe, if that cubic inch was to be expanded so as to fill a globular space whose centre should be the earth, and whose surface should take inside the whole visible creation. Such a medium could convey no mechanical force from the sun, and therefore the medium of space cannot be ponderable. Simple as the argument is, it is unassailable.

ELECTRIC FLUID THE MEDIUM OF SPACE.

Let us take yet another view. All experiments prove that the phenomenon we call electricity, is owing to a disturbance of the equilibrium or natural condition of a highly elastic fluid. In certain conditions of the atmosphere, this fluid is accumulated in the region of the clouds, and by its tension is enabled to force a passage through opposing obstacles, in order to restore the equilibrium. By experiment it is found that dry dense air opposes the greatest obstacle to its escape. As the air is rarefied, this obstacle diminishes; until in a vacuum the transmission may be considered instantaneous. There ought to be, therefore, a greater escape of electricity from the clouds upwards than downwards; and, if space be void, or only filled with an extremely attenuated matter, the electricity of the earth, considered as an elastic fluid without ponderosity, (and no law of condensation from the law of gravity in harmony with its other attributes, will allow us to consider it otherwise,) would long since have left the earth. The same objection applies in the case of the galvanic and magnetic fluids. If we entertain the idea that electricity is a mere disturbance of natural condition, wherein two fluids are united, and that an excess of one is necessarily attended by deficiency in the other, we depart from the first rule of philosophy, which teaches us to admit no greater number of causes than are sufficient to explain the phenomenon. For we fearlessly assert that not a single fact exists in electrical science, which can be explained better on Dufoy’s theory than on Franklin’s; and the former objections would still apply.

NEWTONIAN GRAVITY.

But what is gravity? According to Newton: “Hæc est qualitas omnium in quibus experimenta instituere licet, et propterea per Reg. 3 de universes affirmanda est.” Vide Prin. Lib. Ter. Cor. 2. Prop. vi.

Now the other primary qualities of matter are unaffected by circumstances. The inertia of a particle of matter is the same at Jupiter as on the earth, so also is its extension; but not so with gravity. It depends on other matter, and on its distance from it; and may be less or greater at different times, and in different places. It is, therefore, not philosophical to say that all matter is necessarily ponderous, inasmuch as it is a virtue not residing in itself alone, but needs the existence of other matter to call it into action. If an atom were isolated in space it would have no weight. If influenced by other matter, there must be some physical medium to convey the influence, or gravity is not in accordance with the laws of force and motion. Which horn of the dilemma shall we take? Let us first admit that there is a principle of gravitation, affecting all planetary or atomic matter, and that there exists a highly elastic medium, pervading all space, conveying to us the light of the most distant stars, and that this medium is not affected by gravity. In this summary way, therefore, we have arrived at the pivot on which this theory turns.