2-791-500 - The Print Collector/Heritage Images

Copper station, Nine Elms, Telegraph, 1844. 'Such is its velocity, that when this [Electric Printing Telegraph] shall be laid down the entire line, the time occupied in the transit of a message, from Nine Elms to Portsmouth, and receiving the answer in town, will not exceed two minutes and a quarter...Two instruments, precisely similar, are placed, one at Wimbledon, the other at Nine Elms; the only connexion between them being a single copper wire, conveyed in a thin layer of asphalte. Beneath or near the machine, at Nine Elms, imbedded in the earth, and attached to the apparatus by a copper wire is a plate of copper; and, in like manner, at Wimbledon, a plate of zinc; and these, with the action of the earth's moisture, form a natural battery, complete the electric circuit, and cause the telegraph to perform its various functions. From "Illustrated London News", 1844, Vol I.