by J. Politeyan ; with foreword by R.B. Girdlestone. "The substance of this work was given in a course of lectures in many centers, and also at the... Show moreby J. Politeyan ; with foreword by R.B. Girdlestone. "The substance of this work was given in a course of lectures in many centers, and also at the L.J.S. summer school at Swanswick in 1914"--Pref. Includes bibliographical references (p. 185-186). Show less