460 ENGINEERING ON THE FARM 



2. What size and kind of wire shall be used for the line? 



3. Are more than two wires to be carried on any part 

 of the pole line? 



4. What lengths of poles will be required, and the number 

 of each length? 



5. The telephone instruments to be used. 



Before undertaking to build a telephone line, it would 

 be well to have in hand a complete treatise on the subject. 

 Many useful data regarding specific questions can be 

 obtained from the telephone trade publications. After the 

 available facts have been collected, and definite action is 

 taken on them, a day or two spent with a competent tele- 

 phone engineer will be of great assistance to one in reaching 

 correct conclusions as to procedure. 



BIBLIOGRAPHY 



Jansky, Cyril M., and Faber, Daniel C. Principles of the Tele- 

 phone, Parts I and II. McGraw-Hill. 



Miller, KempsterB. American Telephone Practice. American Elec- 

 trician Co. 



McMeen, Samuel G., and Miller, K. B. Telephony. American 

 School of Correspondence, Scranton, Pa. 



