164 THE ELECTRIC TELEGRAPH. 



Three separate apparatus are required : the perforator, by 

 which groups of holes are printed in the paper ; the trans- 

 mitting or contact key, which is worked by the perforated 

 paper strip ; and the recording instrument of peculiar 

 construction. 



The perforator has a guiding groove, through which a 

 paper strip passes. At the bottom of the groove is an 

 opening to admit of the to-and-fro motions of the upper end 

 of a frame containing three punches, the extremities of which 

 are in a line transverse to the direction of the paper. A 

 separate lever or key is connected with each of the punches 

 for the purpose of elevating them ; the two external ones 

 forming the groups of perforations which make up the 

 message, and the middle one, which is smaller, marking the 

 spaces between the letters and words. On pressing down 

 one of these keys its punch is raised in order to perforate the 

 paper ; at the same time, a clip which holds the paper firmly 

 in its position is lifted up, and the frame containing the 

 punches advances in the groove, the paper being carried 

 forward by the punch which has perforated it. On letting 

 go the key, the paper is first secured by the clip, and then 

 the frame falls back into its normal position. 



The inventor has adopted the Morse alphabet by making 

 the upper line of perforations represent the dots, and the 

 lower the dashes. 



The transmitter receives the slips of paper prepared by 

 the perforator, and transmits voltaic currents corresponding 

 to the holes : positive by the holes on one side, and negative 

 by those on the other. 



An eccentric in the interior produces and regulates the 

 occurrence of three distinct motions : 1st (says the in- 

 ventor) the to-and-fro motion of a small frame which con- 

 tains a groove fitted to receive the slip of paper, and to carry 

 it forward by its advancing motion ; 2nd, the elevation and 

 depression of a spring-clip, which holds the slip of paper 

 firmly during the receding motion, but allows it to move 

 freely during the advancing motion ; 3rd, the simultaneous 

 elevation of three wires placed parallel to each other, resting 



