ABSTRACT
Mechanical phenomena are by their nature more particular, more complicated, and more concrete than geometrical phenomena. Geometrical questions are always completely independent of mechanics, while mechanical questions are closely involved with geometrical considerations—the form of bodies necessarily influencing the phenomena of motion and equilibrium. The other general property relating to equilibrium may be regarded as a necessary complement of the former. Simple motions are a matter of observation, and their combined operation can be understood only through a theory; and again, the compound result being a matter of observation, the simple constituent motions can be ascertained only by reasoning. The object of dynamics is the study of the varied motions produced by continuous forces. The dynamics of varied motions or continuous forces includes two departments—the motion of a point, and that of a body.
