This is a hard cover training course book prepared for employees of the Long Line Dept of A T & T. The title of the book is "Principles of Electricity applied to Telephone ans Telegraph Work. There are 350 pages and you might notice that I have opened the book to the section on the ever popular subject of cross talk. Probably everything you ever wanted to know and a lot more too. The book is in excellent condition. I have two copies of this 1953 book to sell. $17 will get it shipped to your door anywhere in the U.S.