This book is the outgrowth of a course in engineering analysis which the author has developed over the past six years for students in the several branches of engineering at Princeton University. The purpose of the book is to present the essential physical and mathematical principles and methods of approach that underlie the analysis of many practical engineering problems. The point of view is primarily utilitarian in an engineering sense but is aimed at a sound understanding of basic principles and designed to form a firm foundation for more advanced work. The book emphasizes basic physical principles and physical reasoning, and devotes considerable attention to methods of attack, the use of assumptions, procedures in setting up equations, the use of mathematics as a tool in accurate and quantitative reasoning, and the physical interpretation of mathematical results. Graphical methods are used freely, and reasonable approximations arc encouraged provided that they lead to results within the required accuracy. Every effort is made to present the material from a broad and unspecialized point of view and to use material with which every graduate engineer should be familiar, whatever his field.