Wishing to popularize the use of influence (Green's) functions among students of engineering and applied sciences, the author demonstrates the function's uses in classical problems of applied mechanics, as well as problems related to fluid flow, acoustic, electromagnetism, heat transfer, and elasticity. Boundary value problems; bending, natural vibrations, stability, and contact problems for single- and multi-spanned Kirchhoff's beams; two dimensional problems of potential, and other problems are discussed. The author also provides a list of influence functions and matrices. Annotation c. by Book News, Inc., Portland, Or.