THE TELAUTOGRAPH 



In this simple experiment you see the whole prin- 

 ciple of the telautograph, essentially different from 

 the system described in Chapter II. ; the galvano- 

 meter G represents the receiving apparatus, the 

 sketch on copper and the needle tracing over it 

 represent the transmitter. We shall now see how 

 this system works out in practice. A diagram- 



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FIG. 29. 



matic representation of the transmitter is shown in 

 Fig. 29. 



On a substantial iron base two uprights are 

 fixed, and the metal drum D fits on flanges on 

 a steel shaft which turns between centres ; this 

 cylinder is turned true in the lathe. Along the 

 top is a cylindrical steel bar FG, and over this 

 slides a substantial tube PQ to which is fitted 

 the carrier of the steel "pen" or stylus. An 

 arm fitted with a half -nut N projects from one end 

 of the tube, and the right-hand part of the steel 



