A wide range of problems concerning important areas of mathematical physics are associated with applications of Bessel functions. Bessel functions theory is applied to problems of acoustics, radio physics, hydrodynamics, atomic and nuclear physics. Bessel Functions and Their Applications consists of two parts. In Part One, the author presents a clear and rigorous introduction to the theory of Bessel functions and Part Two is devoted to applications to physical problems particularly in mechanics of solids and heat transfer. The volume is intended for engineers and researchers who are interested in the applications of the theory and as such it provides a useful source of reference.