122 THE ELECTRIC TELEGRAPH. 



magnet, whose armature, D, is affixed to one end of the beam 

 A c, and plays between adjusting screws. The beam is 

 supported at z, and has on its shorter arm, A, a connecting 

 rod, B, hinging at h on the horizontal arm of the bent lever 

 h I M, which turns on an axis at x. At M the lever carries 

 the printing-disc, the lower segment of which is immersed 

 in a dish of indian-ink, R. On the axis of this printing disc 

 is a small pulley, p, with a cord passing over, and receiving 

 motion from the pulley p' below. P' is attached to a drum, 

 Q, which revolves with it. The paper strip, shown in the 

 figure by dotted lines, is led to the apparatus from v under- 

 neath a guide-drum, H, at the back of the drum Q, which it 

 rubs against and turns round (thereby imparting a rotary 

 motion to P, P*, and to the printing disc), behind the drum T, 

 over a metal edge, s, and across the stage L o, where the 

 message is read off. The purpose of the metal edge s is t to 

 present a sharp corner of the paper to the printing disc in 

 order that it may receive well-defined marks. 



"When the electro-magnet is in action the armature D is 

 attracted, the connecting-rod lifted up, and the inking disc, 

 which needs not be at a greater distance than half a milli- 

 meter, pressed gently against the paper on the part which is 

 travelling at the moment over the edge s. During this time 

 the motion of the paper keeps the printing disc revolving in 

 the ink, which causes a freshly inked, surface to be always 

 presented. 



78. The Direct Working Ink- Recorder of Beaiidoin and 

 Digney* The difficulties in the way of the arrangement 

 proposed by M. John were well considered by Digney, who 

 modified it accordingly, with the view of rendering it simpler 

 in its construction and surer in its effects. 



Instead of making the printing disc approach the paper 

 strip, Digney lifts the paper up to the disc, which he keeps 

 rotating on a fixed axis, moved by the same mechanism 

 which draws the paper through. Over the top of the disc 

 he places a roller of felt or cloth, moistened with oil colour, 



* " Revue des Applications de 1' lectricit en 18578," par Du Moncel, 

 p. 169. 



