Berliner Gramophone formulations remained the standard disc record material until the first vinyl records – initially made only for radio use and other special applications – were introduced in the 1930s. Beginning in 1896, Berliner's gramophones were made by Philadelphia-based machinist Eldridge Johnson, who added a spring motor to drive the previously hand-rotated turntable. Berliner also opened an office in New York City, staffed by Frank Seaman and O. D. LaDow and organized as the National Gramophone Company. Master recordings were made onto zinc plates, which were then electroplated and a negative-image "mother" made from them to stamp discs. A major reversal
Unusual types of gramophone records 10 cm or 2.75 and 4 inches) make them unplayable on turntables with automatic return tonearms. In the Soviet Union in the 1930s and 1960s, bootleg copies of banned Western music were individually recorded onto used medical x-ray film and sold on the black market. These were called "ribs" or 'Roentgenizdat'. The first discs by Berliner Gramophone were black, and that has been the standard color for gramophone records in times subsequent. As early as 1899, the Vitaphone Talking Machine Co. made records that were brownish-red in color. The American Record Company produced records made of blue shellac for their