ABSTRACT
A diversified American firm, established in 1902, located in St. Paul. 3M is of interest in the sound recording field for its development of magnetic tape players and (1947) “Scotch” recording tapes. Research under direction of Wilfred W. Wetzel led to an improved magnetic tape with an iron oxide coating; this was the Scotch tape. It reached a high frequency of 15,000 Hz, moving at seven and 1/2 inches per second. When this tape went into production in 1947 it almost immediately replaced discs in professional work, such as making of radio transcriptions. The firm has also manufactured videotapes and CD media, and many other nonaudio products. [website: https://www.3m.com./]
A Minneapolis firm, established in 1890 as one of the North American Phonograph Co. affiliates; it was located at 108 Rochester Block. C.H. Chadbourne (or C.N. Chadbourn) was general manager in 1890 and president in 1892.
