MORSE'S TELEGRAPH. 



721 



screw of steel, s, with a blunt point, which serves as a 

 pencil for writing the signals. The spring / pulls the 

 right arm of the lever downwards, and by means of two 

 screws, b and d, the amplitude of the oscillations of the 

 lever is regulated ; b prevents the left arm of the lever 

 from descending so far that armature and poles are 

 brought into direct contact when the current acts, and 

 d prevents the right arm from descending too much by 

 the action of the spring, and thus maintains the arma- 



FIG. 363 (an. proj.; % real size). 



ture at a suitable distance for being attracted. Two 

 small rollers, ww, are turned in contrary directions 

 (the lower one in the direction of a watch hand) by 

 means of clockwork placed between the plates pp } the 

 motion of which is capable of being started or stopped 

 at will by means of turning the handle g either to the 

 left or to the right. When the clockwork is set in 

 motion a band of paper passes onwards between the two 

 rollers, a large quantity of the paper being rolled round 



3 A 



