Royal Signals Museum - Postal Covers - The Wheatstone Automatic Telegraph

The Boer War 1899~1902 - The Wheatstone Automatic Telegraph

The date stamp commemorates the capture of Bloemfontein from Boer control by Field Marshal Lord Roberts on 13 March 1900. After being formally presented with the keys of the town by the Mayor and two members of the Executive Council, Lord Roberts rode into Bloemfontein at the head of the 3rd Cavalry brigade soon after 1300 hrs on 13 March 1900. Just about this time the field line laid behind his advance was broken and the permanent wires to the south along the railway had already been cut. Thus Lord Roberts sent his victory signal by a mounted despatch rider of the Army Signal Service. There was great rivalry and little co-operation between the Signal Service and the Telegraph Sections, and a race developed between them to get the message through first. The Telegraph Section discovered another line to Kimberley via Boshof which had just been occupied by British Troops. There were Boers in between and the line had been cut. Lieutenant H L Mackworth, RE (later Sir Harry) and Sergeant Cadwell rode along this line to Boshof and successfully restored communication. In the process they not only managed to avoid observation by a party of Boers whom they came across but also managed to "borrow" horses to replace their tired ones under cover of the night. By the next evening the line was through to Kimberley and telegraphs passed Lord Roberts victory signal three hours before the mounted orderly arrived.

The Telegraph Sections were equipped with the Wheatstone Automatic Telegraph. The following description is taken from "Technical Instructions", published by the General Post office and contained in "Instruction in Army Telegraphy and Telephony", Vol I,Chap IX, pp 115-6. -"The automatic apparatus consisted of three parts; the perforator. the transmitter and the receiver. A double key, a Galvanometer and a sounder were always required in addition while a rheostat and a condenser were also necessary where speeds in excess of 300 words per minute were desired. The key and sounder enabled the telegraphist in charge of the circuit to obtain and give corrections and acknowledgements or to work by hand when there was not sufficient traffic to demand automatic working. The galvanometer checked the condition of the transmitter and key and also indicated the strength of the current arriving from the distant office. The galvanometer was supplied with a double wound shunt resistance to carry off the extra current generated in the coils. The perforator was purely mechanical in its action. Groups of perforations corresponding to the letters of the alphabet, were made up by it in a slip of oiled paper. which was afterwards propelled automatically through the transmitter."

The Telegraph Section, bottled up in Ladysmith. used an observation balloon connected to the telephone exchange for the direction of artillery fire. and this is depicted also on the cover envelope