[The following note describes a series of volumes and folders and has no documents attached to it. For that reason, a "no Documents found" message will appear if the "List Documents" button at the bottom of the note is used. To see the documents in the volumes and folders described here, use the "Which Series Notes?" button to enter the Series Notes or use the "Next Text" button to move to the first item in the series.]

This collection includes original documents and papers generated by electrical engineer William Joseph Hammer (1858-1934), along with secondary sources assembled by Hammer between 1874 and 1934. The archival record group consists of 107 boxes arranged into four series. A finding aid can be found at the Smithsonian Institution Archives Center website. The selected items primarily cover the years of Hammer's direct involvement with Edison (1879-1889).

Hammer joined the Menlo Park laboratory staff in December 1879, working primarily on the incandescent lamp. In 1880 he became chief engineer of the Edison Lamp Works under general manager Francis R. Upton. A year later, he was sent to London as chief engineer of the Edison Electric Light Co., Ltd. In association with general manager Edward H. Johnson he constructed the Holborn Viaduct central station, which began operation in January 1882. That same year, he installed a large isolated lighting plant at the Crystal Palace Electric Exposition and organized the Edison exhibit at the Paris Electrical Exposition. In 1883 Hammer became chief engineer of the Deutsche Edison Gesellschaft, supervising the installation of central stations in Germany. Upon his return to the United States in 1884, he became an incorporator of the Sprague Electric Railway and Motor Co. and chief inspector of central stations for the Edison Electric Light Co. During 1886-1887 he was chief engineer and general manager of the Boston Edison Electric Illuminating Co. He returned to Europe in 1889 to supervise the installation of Edison's exhibit at the Paris Universal Exposition. After his return to the United States in 1890, he opened an office as a consulting electrical engineer and remained in private practice until 1925. During World War I he was commissioned as a major and was appointed to the general staff of the Army War College, where he conducted valuable research, much of it dealing with the design and construction of aircraft.

Hammer was considerably interested in collecting Edison memorabilia and writing reminiscences about the inventor's career. These items constitute a substantial portion of the ninety-three boxes in the archival collection at the National Museum of American History. He also collected thousands of photographs and assembled a definitive collection of historic and contemporary light bulbs that was exhibited at the 1904 World's Fair in St. Louis. The selected documents consist principally of loose correspondence, letterpress books, and notebooks and other technical material that directly concern Edison and Hammer's work for him. Also included are approximately 70 pages of reminiscences covering the decade of his involvement with the inventor.

Courtesy of the NMAH Archives Center.