166 THE ELECTRIC TELEGRAPH. 



Professor Wheatstone, in his description, shows also how 

 the apparatus may be arranged for translation, and also how 

 it may be used with a magneto- electric machine instead of a 

 voltaic battery, as the source of electric power. 



This excellent method is said to combine the advantages 

 of a five-fold speed in transmission, with a considerably 

 greater security for correctness and legibility. The great 

 difficulty which many people find in acquiring dexterity in 

 manipulating by the present system of Morse, would vanish 

 were such a system of automatic transmission in general use, 

 in which the demand for skill from the employes is reduced 

 to a minimum. 



97. Siemens and Halske's Magneto- Electric Type Telegraph. 

 Towards the end of the year 1861 Messrs. Siemens and 

 Halske succeeded in the construction of a transmitting 

 apparatus which is, at the present time, one of those instru- 

 ments by which an immense amount of work may be got 

 through, with little trouble, in a very short space of time. 



The transmitter, which is automatic, like that of Morse's 

 first electro-magnetic telegraph, is used in conjunction with 

 the polarised ink-recorder already described. 



The transmitter consists of a long insulated wire wound 

 upon a soft iron armature, revolving between the poles of 

 a number of permanent magnets like that of the magneto- 

 electric dial instrument of the same inventors. Of the alter- 

 nate currents thus generated, those which are required to 

 form the signals go through the line to the receiving station ; 

 the others are cut off by an interruption. 



This is effected by the motions of a contact-lever, raised 

 by the teeth of a series of metal types drawn under the lever 

 by the same mechanism which is used to turn the coil. 



Fig. 90 represents a plan of the complete apparatus. L, 

 L 1 is the angular contact lever turning on the axis c. When 

 its point, L, is lifted up, the platinum face on the right side 

 of the upper end, L 1 , comes in contact with the metal screw 

 2 ; and when it falls, the back of L 1 rests against the agate 

 point 1 and breaks the circuit. I, I 1 is the inductor or revolv- 

 ing coil of wire in close proximity to the poles of the perma- 



