15. Force transfers itself from atom to atom without appreciable time. Time being measured by the action of force upon a given quantity of matter, the transfer of force without matter is therefore without time; or with a reduction of the matter, velocity is increased; annihilate the matter, and time is no longer to be affirmed of its passage. Thus attraction of gravitation is spoken of "as a force which is transmitted instantaneously," and so of light, heat, galvanism, &c. So far as they pass in appreciable time it is because they (the forces which move) are connected with the material; the essential quality of pure force unembodied is change of place without appreciable time.

16. Force is diffusible only by contact of the moving atom with another atom. This appears from the fact that force is transferable only when it cannot induce motion, and while space remains there is room for motion. Therefore, the motion of a body must be after a lapse of appreciable time from the contact of the atoms. Consentaneous motion of the mass is from the equal diffusion of motion through its particles. These particles have room for motion before impingement; therefore, the mass moves in appreciable time from the contact of the atoms.

This is finely illustrated by a row of suspended ivory balls through which force is communicated in appreciable time by the measured motion of the balls, according to their distance and the degree of force. It is the foundation of the doctrine of vis inertia. It is not impossible that the distance of atoms constituting a mass may be relatively determined with regard to the distance of atoms in another mass. It will be found that, the more porous the body, the longer is the lapse of time between the impingement and the

motion of the atoms as the mass; we instance equal weights of atmospheric air and of lead. The force is communicated instantly, motion results instantaneously, but time is predicable of the passage of atom to atom, to diffuse the motion equally that it may be consentaneous.

17. Force acts independently of direction; on its transfer, its former line of motion does not necessarily imply a continuance of the same line of motion. A body in motion must continue forever in a state of uniform motion, unless disturbed by the action of an objective cause. The force will be transferred upon impact, and the body receiving it will move in the direction in which it is free to move; or, if the body which obstructs motion be not movable, the force, not being transferred, acts in the opposite direction.

The resultant motion of impinging bodies is demonstrated by the mathematical figure, the "polygon of force," and is equally demonstrable by the diagram showing the contact of atoms having surface; so, too, the angle of incidence and reflection, when a body impinges upon an immovable mass, shows that the resultant motion is determined only by the free space for motion. If two flat surfaces meet, they can be separated only in the opposite direction, if the separating force acts equally on the surface. And so through more complex movements.

We refer to facts of common observation; the rotary motion of the windmill by the horizontal impingement of the wind, the billiard ball, the rise of the wavo. On this action of force, independent of direction, depends the appli cation of force in mechanical combinations, by which the force of falling water is conveyed anywhere, and acts in any direction. Force does not act where it is not; but the me

chanic, availing himself of the laws which govern its transfer, leads it to the loom and opens for it the desired line of motion only.

This doctrine of the transfer of force is one of the foundations of the supposed action and reaction of force; every instance of reaction can be directly traced to the transfer of force.

18. Transfer of force, which does not give the body to which it is transferred consentaneous motion of its atoms, gives vibratory motion to the parts of the mass, or increase of molecular motion, the motion induced being of the same degree as the motion that was suspended. The force being transferred, and motion being in proportion to the force, the vibratory or molecular motion must be the same; or, if the motion of the recipient of the force be retarded, an equal quantity of its force is also turned from the consentaneous motion, so that the resultant motion, internal to the mass, will be doubled; that is, the internal motion is the aggregate of the suspended motion of both impinging masses. Thus, the motion of the tongue of the bell, and of the bell, jointly increase the loudness of its tone; and other instances of this result present themselves to every mind. Hence the concussion and destruction of two balls in opposite motion, which would not result from the motion of either upon the other at rest.

Vibratory motion being the unequal or rather unconsentaneous motion of the parts of a mass, if there be not a gradual increment of motion from the surface to the centre, there will be nodes or points of rest. Thus musical chords manifest certain points of rest.

Vibratory motion being determined by the degree of force,

if the same quantity of matter be moved the same distance, the times of vibration will be the same; if the distance be diminished, there will be an increase of velocity. Tone being dependent on time of vibration, an increase or diminution of force changes the range, preserving the tone. Isochronous vibration is, therefore, a branch of the law which induces the same quantity of motion by the same quantity of force. It follows, too, that there can be no vibratory or reciprocal motion in free space.

19. Force is indestructible. This appears from the general consideration, that what God formed at the beginning no power can destroy. It is imperishable, too, as is evident from its transfer from atom to atom and from mass to mass, and from the state of equable motion, which bodies actuated by a given degree retain. It is also one and identical. That which gives motion is force; if it have different essential properties, these properties cannot be detected, as force is known only by the motion it gives to matter.

There are not differing qualities or kinds of force, which give, this kind, circular motion to bodies, this kind, a straight motion, this kind, motion in a contrary direc tion; nor is there a planetary force, and a molecular force, and an oscillatory force, and a directly acting force; but the one force may act on any element of matter, moving it in any direction, which idea will receive further illustration in the following chapter.

In the research made, the general propositions were extended much further; but up to this point only were they carried with that distinctness which should characterize such propositions. Others remain therefore for further examination.

It will be observed, that an inquiry like the preceding has reference to force mainly as in action, giving to matter place, position, and motion in reference to space, actual, and not apparent or relative motion. We try to consider relative motion only as indicative of true motion, and this as indicative of the laws of force. Thus the ascent of water in the capillary tube is regarded, not as motion in relation to the tube so much as a new rotatory orbit of the elevated water. The log line which is veered from the ship has apparent motion of its own, but the actual motion is that of the ship. This distinction we would recall to the mind of the general reader.