ABSTRACT
Many physical situations involve the simultaneous application of two or more harmonic vibrations to the same system. Examples of this are especially common in acoustics. The general case is of no great importance, but one situation is of great interest and wide application. A phonograph stylus, a microphone diaphragm, or a human eardrum is in general being subjected to a complicated combination of such vibrations, resulting in some over-all pattern of its displacement as a function of time. It is the case in which one has a superposition of a number of simple harmonic motion's, all of the same frequency and amplitude, and with equal successive phase differences. In all such problems the graphical method provides an excellent way of constructing the resultant motion.
