THE LINE BALANCER 



93 



ances are joined in the manner shown, while 

 between the sliding contacts of the resistances is a 

 variable capacity K ; the capacity ranges from o 

 to i microfarad. 



When a photograph is received the waves sent 

 into the line are distorted by their passage through 

 it, and this distortion appears as an elongation of 



Tel e ph on e 

 Lin e 



FIG. 43. 



the chemical dots or marks made upon the paper 

 on the receiving drum as already described ; the 

 greater the distortion the less is the resistance 

 required in RI and R 2 ; the greater the capacity of 

 the line connecting the two machines tKe more the 

 capacity one must introduce by means of K. 



It can now readily be seen how practical the 

 telectrograph is for commercial work. The 

 operator carefully watches the paper on the drum 

 during the first two or three revolutions, and 

 according as the marks are crisp, or blurred he 

 varies the various regulating elements. Hence 



