This book was originally published in 1922. It was written for those who wish to know how to make, use or adjust wireless telephone instruments. The information presented in this book will appeal to those with an interest in the history of radio making. Many of the earliest books, particularly those dating back to 1900s and before, are now extremely scarce and increasingly expensive. We are republishing these classic works in affordable, high quality, modern editions, using the original artwork and text.