XI. APPLICATIONS. 319 



1654. The Original Conducting Wire, as it was made 

 under the direction of the discoverer in 1809-1811, and tested in 

 the Isar. K. Sommering, Frankfort. 



1655. Alarum belonging to Sommering's Telegraph. 



K. Sommering, Frankfort. 



1657. Original Five-Needle Telegraph Dial. 



Council of King's College, from Wheatstone Collection of 

 Physical Apparatus. 



1658. Two-Needle Telegraph. 



Council of King's College, from Wheatstone Collection of 

 Physical Apparatus. 



1659. Three A. B. C. Telegraph Sending Instruments, 



showing gradual improvements. 



Council of King's College, London. 



1660. Horizontal Sending and Receiving A. B. C. 

 Telegraph Instrument. 



Council of King's College, from Wheatstone Collection of 

 Physical Apparatus. 



1661. Two A. B. C. Telegraph Receiving Instruments. 



Council of King's College, from Wheatstone Collection of 

 Physical Apparatus. 



1662. Punching Instrument, for preparing the paper for 

 the transmitter. 



Council of King's College, from Wheatstone Collection of 

 Physical Apparatus. 



1663. Transmitter. 



Council of King's College, from Wheatstone Collection of 

 Physical Apparatus. 



1664. First Electric Key, constructed by Sir Charles 

 Wheatstone. 



Council of King's College, from Wheatstone Collection of 

 Physical Apparatus. 



1665. Wheatstone's First Relay Instrument. 



Council of King' s College, from Wheatstone Collection of 

 Scientific Apparatus. 



1666. Printing Telegraph. 



Council of King's College, from Wheatstone Collection of 

 Physical Apparatus. 



