The present volume on Geodynamics forms Part I of the cooperative treatise
on Theoretical Seismology, of which Part II, Seismometry, by F. W. Sohon, S.J.,
which deals with the instruments and their records, was published in 1932. The
book contains eleven chapters: Stresses in an elastic solid; Elastic strain; Relations
between stress and strain; Elastic body waves; Surface waves on the plane
boundary of an isotropic elastic solid; Vector treatment of elastic waves; Reflection
and refraction of elastic waves; Paths of seismic waves; Interpretation
of seismograms; Determination of epicenters; Depth of focus. The book is of
outstanding value for everybody looking for the details of the classical theory
of earthquake waves. It also gives a good cross section through the results
which have been found from records. The book will be of greatest value for
those interested in the fundamental theory of the propagation of earthquake
waves. "The book has grown out of class room lectures given by the author"
and has been drawn "particularly from the two classical works, Vorlesungen
über Seismometrie by B. Galitzin and The Mathematical Theory of Elasticity by
A. E. Love." It is to be hoped that very soon other volumes will follow on the
problems connected with the origin of earthquakes, and on the recent developments
of the theory of earthquake waves by Jeffreys, several Japanese and
other seismologists
