The text provides a practical, illustrated course on alternating-current power generation, transmission, and distribution, explaining vector summation and phase relationships while surveying single-, two-, and three-phase arrangements and transformer connections. It outlines system classifications, frequency and phase conversion methods, and factors influencing voltage selection and mixed-current practice. Subsequent sections cover auxiliary and switching apparatus in detail, including types of switches, oil and disconnecting breaks, fuses, circuit breakers, inductances, relays, lightning protection, and regulating devices, and offer installation guidance, operational examples, diagrams, and discussion of economy and safety for a.c. systems.