The exact equations of vibrations of a dynamical system consisting of both continuous members and isolated masses are obtained by a new method employing Hamilton's variational equation. The method is quite general, and replaces the treatments by lumped-mass models in current use. It makes possible the calculation of wave solutions, which reveal new features of the nature of the motion. Comparison with the results from lumped-mass models shows the scope and limitations of these results. In some cases it makes possible the deduction of formulas for the stresses in structure members expressed directly in terms of the structural parameters, dispensing with all dynamical calculations. These statements are illustrated by examples.
