372 SEC. 10. ELECTRICITY. 



1690a. Double Indexed Telegraphic Post, with alphabet- 

 ical receiver, indicator, and printer; manipulator on Chambrier's 

 system. M. Dcschicns, Paris. 



The whole of this apparatus is enclosed in a case for protection. 



1691. Stock Exchange or Bourse Telegraph Instru- 

 ment. Siemens and Halske, Berlin. 



A battery is employed only at the central station, from which the messages 

 are sent by depressing lettered finger keys on the transmitter, which are so 

 arranged that the letters most commonly occurring are nearest at hand. Only 

 one line wire is required. The receiving instrument prints in Roman type, 

 and has a double type wheel carrying figures and letters, so that by depressing 

 a changing key in the transmitting apparatus letters or figures may be printed 

 at will. The type wheel automatically returns to its zero position after each 

 printed signal, and is therefore always in adjustment. 



1692. Magnetic Telegraph Apparatus. 



Siemens and Halskc, Berlin. 



The transmitter may be any dial instruments in which the currents are 

 generated by magnets. The receiving instrument prints upon a paper riband 

 from a double type wheel, at the same time indicating on a dial the letters 

 sent. The type wheel is of vulcanised caoutchouc instead of metal. 



1693. Two Automatic Cylinder Transmitters and print- 

 ing instruments working Duplex, i.e., so arranged that messages 

 may be transmitted from both stations simultaneously. 



Siemens and Halskc, Berlin. 



The transmitter is an automatic finger key instrument, in which the letters 

 to be transmitted are for.med in Morse code upon a cylinder of wires, these 

 wires being pushed forward by levers connected with the finger keys, so that 

 by depressing the keys corresponding to the letter to be sent, the complete 

 Morse signal is formed in the wires, which afterwards are brought by revolu- 

 tion of the cylinder into contact with levers connected to the battery and 

 line. 



1694. Automatic Type-printer, including transmitter, re- 

 ceiving instrument, and relays. Siemens and Halske, Berlin. 



The transmitter is an automatic finger key instrument, in which the currents 

 to be transmitted are controlled by a cylinder of wires, these wires being 

 pushed forward by levers connected with the finger keys, so that by depressing 

 the key corresponding to the letter to be sent the necessaiy combination is 

 formed in the wires, which afterwards are brought by revolution of the cylinder 

 into contact with levers connected to the battery and line, and by this means 

 the numbers of currents requisite to bring the type wheel of the receiving 

 instrument to the desired letter are sent into the line. The relay consists of 

 a double armature of aluminium bobbins wound with silk covered wire, which 

 are drawn into or expelled from an intense magnetic field, according to the 

 direction of the current received in the coils from the transmitting instrument, 

 the bobbins causing contact to be made by their movement. The receiving 

 instrument has a double type wheel worked by an escapement, which is 

 actuated by two electro-magnets brought into play by the currents received 

 from the relav. 



