Electromagnetic Telegraphy





Sir Charles Wheatstone and Sir William Fothergill Cooke

The Cooke and Wheatstone Needle Telegraph Systems

References:

  • A Brief History of Railway Signalling
  • Charles Wheatstone
  • Sir Charles Wheatstone (1802 - 1875)
  • Sir Charles Wheatstone - Telegraph
  • Electric Telegraph
  • Needle Telegraphs (1836-1845)
  • The John Milton Williams Telegraph Collection including some needle telegraphs

    • Five Needle System (1837)

    In 1837 W. F. Cooke and Prof C. Wheatstone devised a five needle telegraph system which was installed on the GWR in 1839. This system used a diamond grid of twenty letters with five needles arranged across the middle, deflection of any two needles would point to specific letters on the grid. Obviously having 6 letters missing meant a certain flexibilty was require when sending messages, but the main disadvantage was the need to install and maintain 5 wires. As well as operational messages, it was also used for messages regarding the general business of the railway and also for public messages. 

     

    (Source)                         



    Letter/Needle 1
    		 2
    		 3
    		 4
    		 5
    A
    		CW N N N CCW
    B
    		CW N N CCW N
    C





    D
    		N CW N N CCW
    E
    		 CW N CCW N N
    F
    		N CW N CCW N
    G
    		 N N CW N CCW
    H CW CCW N
    		 N N
    I
    		N CW CCW N N
    J




    K N N CW CCW N
    L
    		 N N N CW CCW
    M
    		 CCW CW N N N
    Letter/Needle 1
    		 2
    		 3
    		 4
    		 5
    N
    		 N CCW CW N N
    O
    		 N N CCW CW N
    P
    		N N N CCW CW
    Q





    R
    		 CCW N CW N N
    S
    		N CCW N CW N
    T
    		 N N CCW N CW
    U




    V
    		 CCW N N CW N
    W
    		 N CCW N N CW
    X




    Y
    		 CCW N N N CW
    Z



                     

    Two Needle System (1844)

    Unfortunately the five needle system only lasted a year before deterioration of the insulation (five wires!) rendered it inoperative. It was replaced by a two wire system which received great publicity when it was used to transmit the news of the birth of Queen Victoria's second son in 1844, and again in 1845 when it was used to send a description of a man wanted for murder when he was seen boarding a train at Slough.

    This system lasted until the end of the 1840's, when it again fell into disrepair and this time was not replaced. Other railways however considered it worth pursuing and by 1845 several railways were installing telegraph systems.

     
            
     
     
     
     

    This page was prepared and is maintained by R. Victor Jones
    Comments to: jones@deas.harvard.edu.

    Last updated March 1, 2004