the present edition is intended to recount these advances so as to present the subject in a present-day light.
The pattern of presentation is based on the assumption that the storage battery is an electrochemical apparatus. As such it is treated first from the standpoint of the chemical, involving the nature and properties of the materials and the reactions which occur during charging and discharging; second, the physical which includes a study of the electrical input and output, the factors which affect the capacity, and the theory of the transformation of chemical energy into electrical energy and vice-versa; third, the engineering applications, including all that is necessary to an adequate understanding of the nature and performance of storage batteries.
The sequence of presentation is a logical one fol the purpose of covering the subject in its entirety, yet portions of the book may be segregated to suit specific interests. After a brief introduction, there is taken up in order the materiMs and methods of manufacture of the different types of cells; the electrolyte including its production, properties, preparation and shipment; theory of reactions, energy transformation and voltage; methods of capcity rating and factors determining capacity; operation which covers charging, discharging, regulation, and sources of trouble; resistance and efficiency; testing for various purposes; present day uses. With regard to uses reference is made to many different applications. They include telephone work, railway service, marine applications, emergency lighting, automotive starting, and aircraft uses.
There is much helpful information in the way of tables, and curves, and formula. In the more technical phases of the subject at appropriate places there are worked out examples. The illustrations also assist greatly to understanding. At the end of the book there is a comprehensive subject index facilitating its use for reference.
The book itself has a flexibility of application. It may be used to advantage by the student of the subject as a whole, by the electro-chemist, by the engineer, by the industrialist, by the electrician, by the service man and others. In fact anyone who uses or has to do with storage batteries may locate in this book something of interest and value. R. H. OPPERMANN.