The concern of _L. Vogelstein & Co._ lost its chief hold on American copper production in 1915. Up to that time L. Vogelstein & Co. worked very closely with group 8 (United States Smelting, Refining & Mining Co.). The output of the United States Smelting Refining & Mining Co. mines and smelters was sold by Vogelstein as well as the output of its electrolytic refinery. But since 1915 this American-owned enterprise itself sells all the copper produced by its own mines and smelters. But Vogelstein still controls the sale of the copper treated at the plant of the United States Metals Refining Co.,[116] over and above what is produced by the United States Smelting, Refining & Mining Co. from its own mines and smelters. This remaining copper consists in part of imported copper, and in part of the output of the Consolidated Arizona Smelting Co., which is an American-owned enterprise. The output was large in 1917 (about 20,000,000 pounds) but three-fourths of it was ore from the United Verde Extension mine. The United Verde Extension has since completed its own smelter and no longer turns over a part of its copper output to Vogelstein through the Consolidated Arizona Smelting Co. The output of United Verde (group 6) also was formerly sold by Vogelstein, but now is sold by the owner of the mine. [116] The United States Metals Refining Co. was a subsidiary of the United States Smelting, Refining & Mining Co., sold, 1920, to the American Metal Co. Therefore, the only copper controlled in 1918 by Vogelstein through selling was about 50,000,000 pounds a year, the output of mines owned by Consolidated Arizona Smelting Co. (about 5,000,000 pounds) and the imported copper, of which about 45,000,000 pounds was treated in 1917. The latter is controlled by Vogelstein not only by selling of the product but in part by smelting contracts and in part probably, as regards South America, by ownership of mines.[117] [117] L. Vogelstein is reported to have sold his interests to the American Metal Co. and subsequently, early in 1920, to have acquired a fifth interest in that company. _Beer, Sondheimer & Co._ has never been a large factor in the United States copper industry, although much interested in zinc. But the firm does control the sale of some copper and owns a smelter at Norfolk. This smelter treats imported ores for the most part, but also obtains some copper from pyrites (sulphur ores) coming from the United States and Canada. Perhaps as much as 10,000,000 pounds of domestic copper was sold by Beer, Sondheimer & Co. in 1917. The company owns an important Cuban mine.