300 SEC. 10. ELECTRICITY. 



168O. Specimen of the First Telegraph Line, 1837. 



R. S. Culley, Esq. 



This specimen of the first Telegraph line was dug up on the railway incline 

 between Euston and Camden. It was laid 'down in connexion with the first 

 experiments made with Cooke and Wheatstone's earliest instrument in 1837. 



15O8c. A portion of the original Telegraph, laid by Sir 

 Francis Ronalds in 1816, in his garden at Hammersmith, and 

 described in his book in 1823. Latimer Clark, Westminster. 



The original wooden model of the dial of the instrument used with the 

 above telegraph. 



1508d. Two Photographs of the Telegraph Apparatus 

 used by Gauss and Weber. 



Physical Institute of the University of Gottingen (Prof. 

 Dr. Riecke). 



The one of the photographs represents the magnetic inductor which serves 

 for giving the signals, the other the unifilar magnetic rod with multiplier 

 serving for receiving the signals. 



SPECIAL COLLECTIONS ILLUSTRATING THE HISTORY OF ELECTRIC 

 TELEGRAPHY, CONTRIBUTED BY H.M. POSTMASTER GENERAL. 



1508e. Cooke and Wheatstone's Earliest Needle Instru- 

 ment, 1837. 



The letters are indicated by the convergence of two needles. The five line- 

 wires required for the instrument were inserted in grooves in a triangular piece 

 of wood, and wire laid underground. 



1509. Cooke and Wheatstone's Four-Needle Telegraph, 

 1838. 



Some of the letters are indicated by the convergence of two needles, as in 

 the five-needle instrument, the rest by one or more movements of the needles 

 to the right or left. 



1510. Alarum with Centrifugal Hammer. Used in con- 

 nexion with Cooke and Wheatstone's first needle instruments. 



Moved by wheelwork and mainspring; released by an electro -magnet, 

 Used in connexion with Cooke and Wheatstone's first needle instruments. 



1511. Single-Needle Instrument, modern form, with drop 

 handle. 



Used by the Electric Telegraph Company. 



1512. Double-Needle Instrument, modern form. 

 Used by the Electric Telegraph Company. 



1513. " Thunder Pump." 



Henley's Magneto-Electric Machine, used for ringing alarums, etc., com- 

 monly known as the " Thunder Pump." Used by the Electric Telegraph 

 Company. 



