Collection includes manuscript copies of more than 3000 patent reviews by Batchelder for the Acoustical Society in the period 1948-1990 and patent correspondence. Engineering Journals "Office Notes" (1929-1952, 6 linear feet) provide a complete history of Batchelder's activities during the period he was employed by Submarine Signal Company and, to a lesser extent, his work after the Raytheon-Submarine Signal Company merger in 1946. The journals contain calculations, technical correspondence, test data, meeting notes, and internal memos associated with all of his activities during the company's formulative, pre-war, and wartime periods. "Sonar in the Germany Navy" (1945) is a comprehensive assessment by Batchelder of German sonar developments during World War II. Also, Batchelder Technical Papers, (1947-1975) contains the unclassified publications during this period (a list of all his papers is available). The archive also holds an early patent (1887) for submarine signals, granted to a great-uncle of Batchelder.