BOOK REVIEWS C. E. PEARSON: Theoretical Elasticity. (Harvard Harvard University Press, 1959. 218 pp., $6.
Srienee, No. 6.)
Tms book is excellent for those already acquainted with elasticity theory but is a rather dilllcult introduction to the subject. It provides a concise account of the present state of the general theory and touches upon most of its aspects, with the obvious exception of Saint-Venant’s Principle. The author has made a valuable contribution to the literature of the field and the many suggestions scattered throughout the book will repay close reading by the active worker. A welcome feature is the inclusion of a clear exposition of the mathematical elements required in treating the subject. The first chapters discuss vector and tensor analysis and the rotation of axes, and the later ehapter on General Solutions starts with an introduction to potential theory. The remainder of the book is devoted to elastirity theory with the emphasis on results in the linear ease. However, the chapter on Deformation fully treats non-linear strain, while the final chapter is concerned with non-linear stress-strain relations. General solutions of the basic equations for a homogeneous body composed of isotropic or anisotropic material are discussed. All the classical methods are mentioned, such as those of Betti and ~~axwell-~orera. Variational principles and approximation methods are treated : besides those of virtual displacement, virtual stress, and Rayleigh-Ritz, that based on the hypercircle terhnique is also described. The account of the latter is elear and comprehensive, unifying many of the conclusions spread through the literature and so is particularly useful. A chapter devoted almost entirely to elementary thermodynamics establishes the ‘ linked ’ thermoelastic equations. Another considers simple forms of elastic wave motion. There are few misprints and the lay-out and printing of the book are good. One minor regret is that insuffl~~ient referenren are provided to original sources. R. J. KNOPR
Proceedings of the 3rd U.S. National Congress Society of kfechanieal Engineers, New York. 884
THIS volume contains the complete text of papers presented at the Congress. There are four general lectures, three of which are concerned with solids: ‘ Linear Thermodynamics ’ by M. A, Biot, ‘ Theories of Creep Buckling ’ by N. J. Hoff, and ‘ Rotationally Symmetric Problems in Elastic Shells ’ by E. Reissner. This preponderance of solid over fluid mechanics at the Congress is to be seen also in the papers themselves. Almost all aspects of the subject are massively represented, an esperial feature being the close blend of theory and experiment in many contributiorls. Interesting new trends and significant advanees are reported over the whole range. This was beyond doubt a quite outstanding Congress. R. HILL
Mechanical Properties Butterworths, London
of Non-metallic Brittle Materials. Edited by W. H. WALTON. New York, 1958. 492 pp., 90s.
THIS is the proceedings of a conference organized by the Mining Researrh Establishment of the Nittional Coal Board in consultation with the Building Research Station, held in London in April,