Collections : [Rare Book & Manuscript Library]

Professional and personal files including Armstrong's correspondence with professional associations, other engineers, and friends, his research notes, circuit diagrams, lectures, articles, legal papers, and other related materials. Of his many inventions and developments, the most important are: 1) the regenerative or feedback circuit, 1912, the first amplified radio reception, 2) the superheterodyne circuit, 1918, the basis of modern radio and radar, 3) superregeneration, 1922, a very simple, high-power receiver now used in emergency mobile service, and 4) frequency modulation - FM, 1933, static-free radio reception of high fidelity. More than half the files concern his many lawsuits, primarily with Radio Corporation of America, over infringement of the Armstrong patents. Litigation continued until 1967. Other files deal with his work in the Marcellus Hartley Research Laboratory at Columbia University, 1913-1935, and with the American Expeditionary Forces in France during World War I, his Air Force contracts for communications development, Army research during World War II, the Radio Club of America, the Institute of Radio Engineers, FM development at his radio station at Alpine, N.J., the use of FM in television, his involvement in Federal Communications Commission hearings and legislation, and his work with the Zenith Radio Corporation. Also, letters to H.J. Round

The Willard L. Severinghaus Papers include the personal and professional papers of Columbia University Physics professor Willard Lesly Severinghaus, as well as a small amount of material related to the extended Severinghaus family. There are also record books from the Terre Haute, Indiana German Methodist Episcopal Church where Severinghaus's father, John F. Severinghaus, was pastor.

Papers of Shepherd, including correspondence with professional colleagues at home and abroad, U.S. government officials, and Latin American government officials dealing with his own publications, his trip to Austria in 1932, and his interest in Latin American affairs, the Institute of Latin American Affairs, the INTER-AMERICAN HISTORICAL SERIES, Latin American area studies, oriental area studies, and the NEW ORIENT SOCIETY. The manuscripts include three boxes of lecture notes on American history in English and German; abstracts and related material of his lecture tour in England, 1922; typescript instructions for his HISTORICAL ATLAS, including maps, related correspondence, and documents; notes, bibliographies, essays, photographs, and related materials on Latin America; a scrapbook of clippings on the Williamstown Institute, 1927; his English literature notebook while an undergraduate at Columbia College, 1893; two boxes and a scrapbook of travel photographs and lantern slides of views from around the world; Shepherd family items include a hand-drawn, hand-colored coat of arms and a letter book of his father, William Shepherd, dated 1867-1871; and Iona Shepherd's 1905 autograph book.