An early magneto wall telephone manufactured in 1917 by Julius Andrae and Sons Co., Milwaukee, Wisconsin, USA from an advertisement in a telephone trade magazine. Shown with the case open revealing internal parts. Magneto telephones were "local battery" instruments; the power to make outgoing calls was provided by dry cell batteries in each telephone, which had to be replaced periodically. These were superseded by modern "central battery" systems, in which all the power for the phone was provided by the local switching office. Alterations to image: Cropped out surrounding advertising copy and partially removed aliasing artifacts (crosshatched lines) added by scanning of halftone photo, using Gimp FFT filter.