Induction motor is one of the most useful mechanical slaves invented by human beings. Therefore, it is worth the most careful study, and the engineers will welcome a good exposition of this theory. They will find it in this book. Dr. Chapman is the designer of Messrs\'s communication machinery. Greenwood and Batty in Leeds. Later, he worked as a senior lecturer and director of the testing department at Faraday House in London. He is now an inspector at the Technical College of the Board of Education. Therefore, his experience has made him qualified in all aspects to write a paper on the motor, especially the induction motor, which he has been specialized in.