Sujet
Copper station
Légende
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.
Crédit
Photo12/Heritage Images/The Print Collector
Notre référence
HRM20B02_346
Model release
NA
Property release
NA
Licence
Droits gérés
Format disponible
56,5Mo (2,9Mo) / 33,7cm x 42,0cm / 3982 x 4960 (300dpi)