HISTORY AND PROGRESS. 127 



cemented into a brass neck, a, supported between screw- 

 points at n, and by the point of the levelling screw, b. 

 The forepart of the brass neck a is cut out in a curve, and 

 forms a gutter, in which the lower part of the printing disc c 

 dips. At d, a round hole in the upper part of the neck, 

 usually covered up by a metal cap, facilitates the filling of 

 the phial. The index e is intended to guide the operator 



Fig. 69. 



in adjusting the niveau of the printing fluid in the phial, so 

 at to cover the requisite segment of the disc c. 



80. Arrangement of a Board with the Direct-working Ink- 

 writer. The direct- working ink-writers of Messrs. Siemens 

 and Halske are mounted on mahogany boards with the trans- 

 mitting keys, galvanoscopes, terminals, and connections. 



The accompanying plan, Fig. 70, gives the arrangement 

 of two boards fitted up with all the apparatus, and properly 

 connected together, as they ,are used at intermediate stations 

 for translation, terminal work, &c. 



On each of the boards are mounted an ink -writer, H, a 

 simple transmitting key, D, a line galvanoscope, B, and twelve 

 terminals for the internal and external connections. 



The five terminals on the right-hand side are filed out, so 

 as to admit a contact peg between their ends and a common 



