In group 3 are two English-owned mines: Arizona Copper Co. (Scotch) and Mountain Copper Co., (English). Ducktown Sulphur, Copper & Iron in the last group (uncertain and unclassifiable) is also English-owned. The combined output of these three English-owned properties is 48,000,000 pounds. This comprises all properties not owned by American capital. Ducktown Sulphur, Copper & Iron Co., Ltd. is English-owned, but all its production (copper matte) is sold to the American Metal Co. The others in the group designated above as uncertain, or unclassifiable, are entirely American owned, although their production has been marketed by the American Metal Co. or L. Vogelstein, as discussed later. None of these groups actually own the mines outright, the mines being owned by hosts of stockholders scattered all over the country. Of many companies the president and directors own a very small percentage of the stock. As regards group 6 and to a less extent group 4, however, the actual ownership is in very few hands; but this is exceptional. The copper mines of the United States, like the railroads and the largest industrial enterprises, such as the United States Steel Corporation, etc., are, in the last analysis, controlled by their stockholders. Summarized on the basis of the 1917 output, one finds that the ownership of American copper mines is as follows: American 97¹⁄₂ per cent., English and Scotch, 2¹⁄₂ per cent. _Control Through Ownership of Smelters and Refineries._--Ownership of smelters that treat domestic ore is substantially identical to the mine ownership given above. Interests owning active smelters are less numerous than interests owning mines, because efficient smelting requires large-scale operations. The electrolytic refineries are all American owned. Large-scale units, representing heavy capital investments, are essential in electrolytic refining. A small refinery cannot compete successfully with large ones. The average important copper mine produces enough ore to make about 25,000,000 pounds a year, whereas the average smelter produces three or four times as much blister or casting copper, and the average electrolytic refinery can produce over 250,000,000 pounds annually. Consequently, there are only six groups (Hayden-Jackling, Morgan-Guggenheim, Rockefeller-Ryan, Phelps-Dodge, Calumet & Hecla, and U. S. Smelting, Refining & Mining Co.) interested in refinery ownership. No small producer has the capital or the size to be able to enter this field. Table 39 shows electrolytic copper refineries of the United States and their ownerships: TABLE 39.--OWNERSHIP AND CAPACITY OF AMERICAN COPPER REFINERIES