The visible and tangible creation into which we are introduced at our birth, is not, in all its parts, fixed and stationary. Motion or change of place, regular or occasional, belongs to all or most of the things which are around us. Animal life everywhere moves; the earth itself has its motion, and its complexities of motion; the ocean heaves and subsides; rivers run, lingering or rushing, to the sea; and the air which we breathe moves and acts with mighty power. Motion, thus pertaining to the physical objects which surround us, is the exhaustless fountain whence philosophy draws the means by which, in various degrees and endless forms, natural agencies and the tendencies of inert matter are brought to the succor and assistance of human strength. It is the object of mechanical contrivance to modify motion, to produce it in new forms, to direct it to new purposes, to multiply its uses, by its means to do better that which human strength could do without its aid, and to perform that, also, which such strength, unassisted by art, could not perform. Motion itself is but the result of force; or, in other words, force is defined to be whatever tends to produce motion. The operation of forces, therefore, on bodies, is the broad field which is open for that philosophical examination, the results of which it is the business of mechanical contrivance to apply. The leading forces or sources of motion are, as is well known, the power of animals, gravity, heat, the winds, and water. There are various others of less power, or of more difficult application. Mechanical philosophy, therefore, may be said to be that science which instructs us in the knowledge of natural moving powers, animate or inanimate; in the manner of modifying those powers, and of increasing the intensity of some of them by artificial means, such as heat and electricity; and in applying the varieties of force and motion, thus derived from natural agencies, to the arts of life. This is the object of mechanical philosophy. None can doubt, certainly, the high importance of this sort of knowledge, or fail to see how suitable it is to the elevated rank and the dignity of reasoning beings. Man's grand distinction is his intellect, his mental capacity. It is this which renders him highly and peculiarly responsible to his Creator. It is on account of this, that the rule over other animals is established in his hands; and it is this, mainly, which enables him to exercise dominion over the powers of nature, and to subdue them to himself.