XI. APPLICATIONS. 317 



1610. Copy of the Electro-magnetic Telegraphic Appa- 

 ratus of Gauss and Weber, of Gottingen, made and used from 1833 

 to 1838. Attached to this are 



(a.) The signal giver (by means of induced current). 



(b.) The signal receiver (a magnetic rod with multiplying coil 

 and mirror). 



(c.) Telescope for reading off the deflexions of the magnet ; with 

 stand. 



1611. Copy of the Electro-magnetic Telegraphic Appa- 

 ratus of Steinheil, in Miinchen, 1837. 



1612. Electro-Magnetic Indicator, combined with a type- 

 printing apparatus of Siemens, of Berlin, constructed in 1846. 

 Patented for Prussia. 



1613. Bell Machinery for Railways (Siemens'), 1847. 



1614. First Gutta-percha Press for covering conductors 

 with isolating material without a seam. After Siemens' model, 

 and constructed by Fourobert and Bruchner. By machines after 

 this model numerous subterranean lines in Germany and Russia 

 were constructed from 1847 to 1851, and submarine lines are now 

 made in the same manner. 



1615. Plate Lightning Conductor, employed first by Sie- 

 mens in 1848 between Eisenach and Frankfort. 



1616. Double Style Apparatus, with writer in relief 

 (Siemens). 



Constructed by Siemens in 1853. The lines made by Siemens and Halske, 

 the Warsaw-Petersburg, and other telegraph lines, were at first worked with 

 apparatus of this system. 



1617. Polarized Relay for the above. Oldest form without 

 a steel magnet. The magnetic induction of the core and keeper is 

 effected by a branch current of the local battery. (Siemens, 1851.) 



1618. Key for the above. 



1619. Magneto-electric Current Generator, with 28 pairs 

 of magnets. 



1620. Dynamic Mine Exploder (Siemens, 1850). 



1621. Polarized Belay for Double-style Apparatus, 



with steel magnets (Siemens, 1852). 



1622. Hand-puncher for Self-acting Sender. 



1623. Feeder for above. 



1624. Receiver for above (Morse with suspended magnets). 



