PREFACE This book has been written especially for those who want to learn how to install electrical wiring, in a manner satisfactory to the owner of the building, and at the same time complying with electrical Codes so that the finished job may be acceptable also to electrical inspectors, power companies, and others having jurisdiction in the matter. Electrical wiring cannot be learned by skimming through this or any other book for 15 minutes, but careful study of this book together with investigation of such local ordinances as there may be, and observation of local cus- toms, should enable anyone to make an installation in a residence or farm, acceptable to everyone concerned. However, before doing any wiring, learn how to do the job correctly. or hire an electrician who knows how. The author hopes this book will also be of considerable value to anyone planning an electrical installation (re- gardless of who is to do the work), to enable him to write sensible specifications which will lead to his secur- ing the greatest usefulness from electricity. Careful planning will do away with later changes which usually cost twice as much as when included in the original plans. Finally, the book may be interesting to the man who is just naturally curious, and wants to know how things are done and why—the man who still has in himself some- thing of the spirit of the boy who takes the clock apart just to see what makes the wheels go around. Throughout this book there have been emphasized the reasons why things are done in a particular way, so that you will understand not only the exact problems dis- cussed, but will also be able to solve other similar prob- lems as they arise in actual wiring of all kinds. Suggestions for the improvement of this book will be greatly appreciated by the author. H.P. RICHTER