Montessus de Ballore was one of the founders of scientific seismology. A pioneer at the same level of Perrey, Mallet, Milne, and Omori, he developed a fascination with earthquakes and volcanoes while taking part in a French military mission to El Salvador (1881-85). Back in France, he began publishing his research on seismology in various academic journals and in 1888 he was awarded a prize by the Paris Academy of Sciences for his original thesis. Following the 1906 Valparaiso Earthquake, which destroyed much of central Chile, Montessus de Ballore was hired by the Chilean government to direct the new Seismological Service. During his tenure (1907-23), he carried out an impressive project on the collection and interpretation of worldwide earthquake data. Many of his ideas laid the groundwork for later discoveries. This book, which discusses the physical principles obtained through a synthesis of the enormous quantity of data he had gathered, is no exception, and includes a preface by the eminent Viennese scientist Edouard Suess. Tall octavo: vii, 579 p. with a frontispiece, 221 figures (some folding), and 63 tables. In a three-quarter black morocco over marbled paper binding, with decorative gilt stamping, five raised bands, marbled endpapers, and a ribbon marker. Short tear to the fore-edge of the title page, with two ink ownership stamps to a prefatory blank leaf. Some general shelfwear to the boards, including a bit of mild bumping to the corners; otherwise very good.