Evolution of Telephones 69 



" How does the telephone work? " is a 

 question that must often have been asked 

 of father. And father, having had a busy 

 day, in which, perhaps, his telephone has 

 annoyed rather than helped, will not give 

 a satisfying answer. Well, of course, like 

 all electrical gadgets it is a little intricate, 

 and you would not thank me to go too 

 deeply into details. Here is something of 

 what takes place when a call is required. 



There are three distinct parts of the tele- 

 phone which you and I know these are 

 fairly simple. In the Exchange there are 

 thousands of parts, which would take a 

 whole book to explain. The three parts 

 that matter at the moment, are the trans- 

 mitter, the line wires, and the receiver 

 items one and three are similar. The 

 receiver (and transmitter) consists of a 

 horseshoe magnet, fitted with a small exten- 

 sion piece of soft iron at each end. The 

 magnet is placed very near to the centre 

 of a disc of thin sheet iron, the centre of 

 which is inclined slightly towards the poles 

 of the magnet. Round each pole of the 



