electric machine telegraph 19th century stock operated morse depicting pneumatically engraving perforating dated palace telegraphs exhibition shown crystal international alamy
telegraph women championed employment
telegraph hughes invented found england
telegraph alamy stock machine alphonse needle receiver developed 1842 electrical
telegraph merchants engraving 1854 electrical stock alamy inventor prize nobel radio
telegraph machine museum science london stock electric kensington charles england south printing alamy wheatstone dated 1841
telegraph electric mediterranean apparatus recording automatic stock alamy electricity carrying poles cables experiments velocity against sky