KING'S COLLEGE LONDON / SCIENCE PHOTO LIBRARY KING'S COLLEGE LONDON / SCIENCE PHOTO LIBRARY
Early galvanometer. The electric current passes through the electromagnetic coils at lower centre. The rod suspended above the coils at centre rotates as it is deflected, allowing a reading to be taken from the dial. German physicists Johann Schweigger and Johann Poggendorff independently built the first galvanometers in 1820 and 1821. Artwork from an 1873 edition of a German book on the application of electromagnetism to the new technology of telegraphy.
Model release not required. Property release not required.